NATIONAL

OPTICAL

ASTRONOMY

OBSERVATORIES

Sidney C WolffNOAO/DIR

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

Cerro Tololo Inter-American ObservatoryKitt Peak National Observatory

National Solar Observatory

La Serena, ChileTucson, Arizona 85726

Sunspot, New Mexico 88349

ANNUAL REPORT

October 1996 - September 1997

October 30,1997

TABLE OF CONTENTS

L INTRODUCTION

IL AURA BOARD

m. SCffiNTDJIC PROGRAM

A. Cerro Tololo Inter-American Observatory (CTIO)1. The Search for High Z Supernovae2. Nearby Stars and Planets 2

B. Kitt Peak National Observatory (KPNO) 31. The History of Star Formation in Distant Galaxies 32. Oxygen Abundance and the Age of the Universe 43. The Age of Elliptical Galaxies - Is There Enough Time? 5

C. National Solar Observatory (NSO) 51. Results from GONG 5

2. High-Resolution Images of Solar Magnetic Fields 63. Active Optics Control Loop Closed at the Sac Peak Vacuum Tower Telescope 7

IV. DIVISION OPERATIONS 7

A. CTIO 7

Telescope Upgrades and Instrumentation 71. 4-m Upgrades 82. Major Instrumentation Efforts 93. SOAR 4-m Telescope Project 94. CCD Implementation and ARCON Controller Development 105. Existing Small General-User Telescopes on Cerro Tololo 106. New "Tenant" Installations and Upgrades 107. Other 11

B. KPNO 12

1. Image Quality Improvements 122. WTYN Queue Observing Experiment 123. WTYN 13

4. KPNO Instrumentation Improvements 145. Burrell-Schmidt 14

C. NSO 15

1. Kitt Peak 15

2. Sacramento Peak 17

3. Digital Library Development 21

D. USGP/ScOpe 21

E. NOAO Instrumentation 251. CCD Mosaic Imager 262. Phoenix 263. Hydra for CTIO 264. SQIID Upgrade 275. Gemini IR Array Controllers 276. Gemini Near-IR Spectrometer 277. High-Efficiency Spectrograph 28

V. MAJOR PROJECTS 28

A. GONG 28B. RISE/PSPT 30C. SOLIS 32D. CLEAR 33E. SOAR 34

VI. CENTRAL COMPUTER SERVICES 34

A. Tucson 34

B. Mountain Programming Group 35C. CTIO - La Serena 35D. CTIO -Communications 36E. NSO-Sunspot 36

Vn. SCIENTIFIC STAFF 36

A. Hired 36B. Completed Employment 37C. Changed Status '. 37

Vffl. DIRECTOR'S OFFICE „ 37

EX. NOAO STATISTICS , 38

A. CTIO 38B. KPNO 39C. NSO '40D. NOAO Tucson Headquarters Building 41

APPENDICES

Appendix AAppendix BAppendix CAppendix D

NOAO Technical Reports ListCTIO Publications List

KPNO Publications List

NSO Publications List

L INTRODUCTION

This report covers the period 1 October 1996 - 30 September 1997.

The National Optical Astronomy Observatories (NOAO) are operated by the Association ofUniversities for Research in Astronomy, Inc. (AURA), for the National Science Foundation (NSF).The four divisions of the NOAO are: the Cerro Tololo Inter-American Observatory (CTIO) innorthern Chile; the Kitt Peak National Observatory (KPNO) near Tucson; the National SolarObservatory (NSO) with facilities on Kitt Peak and at Sacramento Peak, New Mexico; and the USGemini Program (USGP) based in Tucson. NOAO observing and data reduction facilities areavailable to the entire astronomical community. The NOAO Home Page contains on-lineinformation about NOAO services, including telescope schedules and instrument availability, andinformation about how to apply for telescope time. The NOAO Home Page can be accessed throughthe World Wide Web at http://www.noao.edu/.

IL AURA BOARD

AURA is a private, non-profit corporation that operates world-class astronomical observatoriesthrough its "operating centers." NOAO is an operating center managed by AURA, undercooperative agreement with NSF. There are thirty-one AURA member institutions, including fourinternational affiliates. The member institutional representatives elect a governing Board ofDirectors: thirteen members, including the President, ex-officio. In addition to NOAO, AURAoperates and manages the Space Telescope Science Institute under contract with NASA, and theInternational Gemini Project under cooperative agreement with the NSF on behalf of six partnercountries.

m. SCIENTIFIC PROGRAM

Several hundred papers are published each year based on data from NOAO. A sample of recentwork is described in this section of the report.

A. Cerro Tololo Inter-American Observatory (CTIO)

1. The Search for High Z Supernovae

It has long been known that modeling the observed Hubble Diagram (the magnitude-redshift relation) could lead to the determination of cosmological parameters if"standard candles" of sufficient luminosity could be found and calibrated for use atlarge redshift (z - 0.3 - 0.6). The recent work of M. Hamuy (U. of Arizona) andcollaborators (carried out with CTIO telescopes and reported in the December 1996Astronomical Journal) establishes the type la supernova as such a calibrated standardcandle.

After an initial find of a single object by a Danish group at ESO in 1989 and withstandard candle in hand, two groups have made extensive use of CTIO facilities in thepast year to carry out searches for high z supernovae in order to determine or constrainthe cosmological parameters Q.M (the mean matter density parameter) and Q.A (thevacuum energy density parameter). The high z searches will help to place limits on theseparameters for certain cosmologies and may eventually answer the long standing

question about the type of universe we inhabit: is it open, closed, or flat? The twogroups involved are: S. Perlmutter (Lawrence Berkeley Labs.) and collaborators,collectively known as the Supernova Cosmology Project (SCP), and B. Schmidt (Mt.Stromolo Obs., Australia), N. Suntzeff (CTIO), and collaborators.

The primary problem with using the type la supernovae as cosmological probes (asidefrom understanding their characteristics as standard candles) is that they are randomevents which last only a relatively short time. Finding them is a statistical process whichrequires covering a large area of sky down to faint limiting magnitudes. Both groupshave been successful in large part due to the image quality at the CTIO 4-m combinedwith the large areal coverage and sensitivity provided by the Big Throughput Camera(BTC). The BTC is a visitor instrument currently available for use at CTIO. It wasdeveloped by A. Tyson (Bell Labs., Lucent Technologies) and G. Bernstein (U. ofMichigan) and employs a mosaic of four 2048 x 2048 CCDs covering 0.25 sq. degreesin a single exposure. Both supernova groups employ a number of other telescopes(including the MMT, CFHT, HST, WIYN, and Keck) in the post-discovery phase totrack the light curves (necessary to obtain the intrinsic luminosity of a given supernova)and obtainspectra(necessary to distinguish the type la's from other types and obtain theredshift).

The SCP and Schmidt, et al. groups have so far each found roughly 30 type la's in therequired redshift range. Preliminary results suggest a near critical value of the densityparameter for a universe with no vacuum energy density (see Perlmutter, et al. in theJuly 1997 issue of the Astrophysical Journal) and that the local and global values of theHubble constant (H0, the present expansion rate of the universe) do not differ by morethan about 10% in a flat or zero vacuum energy density universe (see Kim, et al. in theFebruary 1997 issue of the Astrophysical Journal).

2. Nearby Stars and Planets

Several groups are currently utilizing CTIO telescopes to search for objects at the otherend of the astrophysical luminosity scale from type la supernovae. These are the ongoing programs designed to find new solar neighbors within 10 pc, the ResearchConsortium on Nearby Stars (RECONS) project, and the Probing Lensing AnomaliesNETwork (PLANET) collaboration which is doing follow-on monitoring ofmicrolensing events toward the Galactic bulge.

a. RECONS, a project of T. Henry (STScI) and collaborators, is searching a volumeof space 10 pc in radius for as yet undiscovered solar neighbors. They estimate anadditional 130 systems have yet to be found in this volume if the density of stellarsystems is the same as that in the volume out to 5 pc radius from the Sun.RECONS is systematically characterizing the coolest (M type) dwarfs in thenearby sample with new JHK photometry, red spectroscopy, and speckle imagesdesigned to detect companions. The cool dwarf stars contribute as much as 70% ofthe Galaxy's stars by number, about 50% by mass. In addition to seeking newmembers of the solar neighborhood, the RECONS project plans to obtain goodinfrared photometry for the entire sample of nearby stars (combined with opticalphotometry from the literature) and spectra for all the faintest (Mv > 8.0) Mdwarfs to determine the local mass and luminosity functions to a very high degreeof accuracy. These data can be used to study the transition between stellar and

sub-stellar objects, Galactic structure, and the star-formation process through abetter knowledge of observed stellar multiplicity.

Much of the near infrared photometry and red spectroscopy have been carried outon the CTIO 1.5-m telescope with the facility infrared imager, CIRIM, and on theCTIO 4-m Blanco telescope using the R-C spectrograph. This includes work doneon LHS 1565, which RECONS has established as the 20th nearest stellar system tothe Sun (see their article in the July 1997 issue of the Astronomical Journal). Themost recent CTIO observing session for RECONS promises exciting results for thefuture: they have identified a number of new solar neighbors as well as new "ultracool dwarfs," including several likely brown dwarfs.

b. The PLANET collaboration, organized by P. Sackett (Kapteyn Lab.), beganextensive monitoring of Galactic bulge microlensing events this year at CTIOusing the 0.9-m telescope. The collaboration makes use of telescopes throughoutthe southern hemisphere to follow the events 24 hours per day. Microlens huntingcollaborations monitor millions of stars toward the bulge each night during thesouthern winter. Occasionally one of the bulge stars will be magnified(brightened) as a foreground object passes through the line of sight to the bulgestar. The gravitational field of this foreground "lens" is responsible for "focusing"the bulge star light and enhancingits brightness by an amount given by the generaltheory of relativity. These lensing events may last from days to months if the lensobjects are typical stars. In addition to the primary lens event, secondary lensingevents can occur on a much shorter timescale if there is a planet circling the lens.These events appear as "spikes" on the light curve of the primary lensing eventand may last as little as a few hours for earth-size planets.

The short timescale of the secondary lensing event is the reason PLANET needs24 hour coverage of bulge microlensing events. The current microlensing groupsare detecting bulge events at a sufficient rate to guarantee PLANET enoughobjects to monitor during each of their scheduled telescope runs. PLANETobserving runs this season at CTIO were monitoring about eight events each night.The probability of detecting an earth-size planet around a typical lens is about 3%.This is large enough that PLANET will detect such objects given the current ratesof bulge events if earth-size planets are common. If not, PLANET will findinteresting limits to their possible number. Other short timescale events can occuron top of a lensing event, for example, the presence of a multiple stellar lens.PLANET has successfully observed an event of this type, demonstrating theirability to detect short timescale events.

B. Kitt Peak National Observatory (KPNO)

1. The History of Star Formation in Distant Galaxies

One of the most basic issues in extragalactic astronomy is the origin and evolution ofgalaxies. As more sophisticated technology becomes available, observers are able togather much greater detail about this process. Basic questions concerning the first onsetof star formation in galaxies, the presence or absence of subsequent epochs of starformation, and the influence of early galactic environment and galaxy-galaxy encountersare now on the verge of being answered.

One of the richest fields for gathering information about these issues is the Hubble DeepField (HDF). The area of the sky covered by the Hubble Deep Field has been imaged tofainter levels than any other portion of the celestial sphere. Many new and excitingresults are emerging from the multicolor image, and there are even indications that wemay be seeing all the galaxies there are to see in this region. However, the Hubbletelescope does not "see" in the infrared, and for many very distant objects thecosmological redshift moves many indices of star formation and stellar activity into thiswavelength regime. Thus a deep infrared image of the same portion of the sky ascovered by the Hubble Deep Field can provide essential complementary informationthat will allow us to examine the evolution of galaxies and stellar populations withcosmic epoch. Such deep IR observations of the HDF have recently been made by AndyConnolly (JHU), Mark Dickinson (JHU), Matt Bershady (Penn State), Peter Eisenhardt(JPL), Richard Elston (Florida), and Adam Stanford (LLNL). These observers used theKPNO 4-m telescope with the IRIM camera to observe the HDF for 10 nights in the J,H, and K passbands.

Using the infrared data together with already existing data at optical wavelengths,Connolly et al. are able to derive the co-moving luminosity density of galaxies in threeredshift ranges: 0.5-1.0, 1.0-1.5, and 1.5-2.0. Assuming the galaxy distribution inluminosity is similar to that found locally, these data can then be used to derive metalenrichment rates and hence inform us about the star formation rates as a function ofredshift. It is important to note that the majority of these galaxies are either spiral or"disturbed" objects, as opposed to elliptical galaxies which may have a very differenthistory (see item 3 below). These data show that there is a rise in star formation from aredshift of about 4 until a peak star formation rate is reached at a redshift of 1.5. Therate then declines rapidly from 1.5 to the present. This picture of fast evolution of thestellar population of galaxies is now well established, and it presents a serious challengeto be met by theoretical modeling of galaxy formation and evolution.

2. Oxygen Abundance and the Age of the Universe

A majorproblem with many currently popular cosmological models is that they predictan age of the Universe that may be in direct conflict with the inferred ages of the oldeststars found in globular clusters. However, age determinations of the stars in globularclusters are also subject to assumptions about abundance ratios and uncertainties aboutthe processes occurring in stellar interiors. One such parameter is the ratio of oxygen toiron abundances in the old stars in our galaxy. Stars in the galactic halo and many starsin globular clusters have a higher oxygen to iron ratio than that found in the Sun, butsome stars in the clusters show deficiencies of oxygen relative to iron. This deficiencyseems to occur in the more luminous stars, and the supposition is that oxygen is burneddeep in the interiors, where it is carried by convection. This idea can be tested byobserving oxygen abundances in less evolved stars in clusters, and Caty Pilachowskiand Taft Armandroff (NOAO) have carried out such a program. Using the KPNO 4-mtelescope with the Hydra spectrograph, they have examined 40 stars in the cluster Ml3,and they find for these relatively unevolved stars that the oxygen to iron ratio is onaverage about one-tenth the solar value. This unexpected result implies that eitheroxygen is consumed at an earlier stellar age than previously thought or that there existsignificant oxygen variations from cluster to cluster. In either case this serves as a

warning against the common assumption of uniform abundance ratios when determiningthe ages of globular clusters.

3. The Age of Elliptical Galaxies - Is There Enough Time?

Over a decade ago, observations of galaxies in nearby clusters revealed what is nowknown as the Butcher-Oemler effect, namely that there seems to be an increase in bluegalaxies as one goes back in cosmic time. This effect has become well documented,especially with data from HST and most recently the Hubble Deep Field. Butintermingled with these blue, disk-like and presumably star forming galaxies has been apersistent and disquieting presence of what appear to be old, evolved and stable galaxiessimilar to the population of nearby elliptical galaxies. If these objects are seen at earlierand earlier cosmic epochs, they will eventually pose a serious threat to currentcosmologies in that the models will not provide enough time for these quiescent systemsto form and develop old stellar populations. An attempt to define more accurately theformation epoch of elliptical galaxies has been carried out by Adam Stanford (LLNL),Peter Eisenhardt (JPL), and Mark Dickinson (JHU) using the KPNO 4-m and 2.1-mtelescopes during the past four years. These observers looked for variations or scatter inthe colors of elliptical galaxies as a function of redshift; conventional Cold Dark Mattercosmologies predict an increase in such scatter with increasing redshift. However, theresults of this set of observations show less scatter than predicted, and in fact the dataare consistent with a single starburst formation at redshifts of order or greater than 4,followed by passive evolution. This is in contrast to the evolutionary history of "disky"systems that is described in IU.B.l., and it provides a major task for galaxy evolutiontheory to model these two populations of objects. The inconsistency of the observationsof elliptical galaxies with CDM models provides an important indicator that our currentcosmological thinking may need serious revisions.

C. National Solar Observatory (NSO)

1. Results from GONG

The GONG network became operational in late 1995, and it is living up to our hopes interms of operational reliability, observing duty cycle, instrument performance, and dataprocessing capabilities. It is fulfilling its scientific promise as well!

GONG was undertaken to test models of stellar internal structure and dynamics, and toexplore the interior with these new techniques. Much of the analysis to date has focusedon the structure of the base of the convection zone where differential rotation rapidlydisappears inward (the so-called tachocline), where sound speed anomalies compared tomodels are their most striking (presumably arising from shear-driven waves and/orinstabilities, and convective overshoot) and where the putative dynamo is believed toreside. It appears that convective overshoot below the unstable zone is quite small, lessthan a few percent of the scale height, and that the additional mixing required to accountfor the sound speed anomalies may be described, to some extent, by recent models ofstellar evolution. But, this is a very preliminary result, as in fact are most to date.Constraints on a magnetic field at the base of the convection zone are being drivenbelow a megagauss by GONG observations: down to a few hundred thousand, for themoment. Possibly most intriguing are the results on the thickness and shape of thetachocline itself. While at the very limit of the present analysis of the data, the

tachocline appears to lie below the base of the convection zone and be barely resolvedin radius. There is a suggestion that it may move slightly closer to the surface at higherlatitude. Again, this is all very much "work in progress".

Now that we are getting such high signal-to-noise data, in terms of the instruments'performance and of the network's performance in removing the "daily sidelobes", aswell as simultaneous acquisition of velocity, intensity, line strength measurements, andthe homogeneity of the resulting data, we are discovering all sorts of new challengesassociated with the inference of the frequencies of the solar resonant modes ofoscillation. As a result, many of the simplifying assumptions that had proven expedientin the past are being challenged. For example, the surface motions of the oscillations arenot simply vertical, and the influence that this has on our analysis of what combinationof modes gives rise to the observed velocity fields is proving quite challenging tountangle. Possibly most intriguing is the observation that the asymmetry of the lineprofiles are of opposite sign for velocity and intensity oscillations, and as a result theinferred resonant mode frequencies can differ significantly for the two signals. On theone hand, there is the intriguing physics problem of understanding why this occurs, andon the other we are grappling with the impact of these systematic shifts on ourinversions of internal structure. With the improved signal-to-noise data, we are alreadyseeing solar activity induced changes in the frequency, even at the minimum of solaractivity. We also now appreciate what a goodjob that GONG can do in the area of localhelioseismology as well, but major strides forward in this area await the new, higher-resolution camera.

While the principal scientific issues are helioseismic, the GONG data providecontinuous measurements of the surface velocities themselves, and magnetograms withbetter than one hour sampling. Magnetograms obtained elsewhere around the world,once per day or for a small fraction of a day, miss important aspects of the evolution ofthe magnetic fields that occurs on a timescale of hours, and which GONG captures.Even with the present low-spatial-resolution camera, quite interesting ancillary scienceis emerging and this "extra" GONG science will only increase in importance as solaractivity starts to increase.

Stay tuned, GONG is just warming up.

2. High-Resolution Images of Solar Magnetic Fields

Magnetic elements are the fundamental structures of the solar magnetic field in plages,in active regions, and in the network along the boundaries of supergranular cells. Theyhave a field strength of 1-2 kG in the lower photosphere and diameters on the order of100 km, which is comparable to the diffraction limit of the biggest solar telescopes.Occasional magnetograms at a resolution of about 0.5 arcsec have been recorded underexcellent seeing conditions, but seeing normally prevents the resolution of magneticelements. The currently most favored theoretical models of magnetic elements are theso-called flux tubes. These flux tubes appear brighter than the average photosphere,since we see deeper and hotter layers in the partly evacuated flux tube.

Speckle interferometric techniques can greatly improve the spatial resolution of solarobservations. The speckle deconvolution technique developed by Christoph Keller andOskar von der Luehe is able to produce diffraction-limited images of the Sun in very

narrow spectral bands by combining short-exposure images from a narrow and a broadband channel. The broad-band images are reconstructed using a modified Knox-Thompson algorithm. By applying this technique to polarimetric observations in thewing of a Zeeman-sensitive spectral line, a few magnetic flux tubes have been resolvedin the past.

Hundreds of flux tubes in the quiet network are now being studied based onobservations at the 76-cm Sacramento Peak Vacuum Tower Telescope with the ZurichImaging Stokes Polarimeter (ZIMPOL) I, using the Universal Birefringent Filter with abandwidth of 25 pm in the Cal line at 610.3 nm. Three hundred simultaneous images inthe broad-band and the narrow-band channels with a field of view of 14 x 14 arcsec

were collected within less than one minute for each area. Bruce Wilton, an NSOsummer student supervised by Christoph Keller, has analyzed more than 60 regions inthe quiet network. Many of these magnetograms have a resolution close to 0.2 arcsec.Preliminary results indicate that we barely resolve the larger elements. Most magneticelements in the network seem to be brighter than the average intensity in white light atdisk center, which is in contrast to the dark structures seen in plages at disk center.

3. Active Optics Control Loop Closed at the Sac Peak Vacuum Tower Telescope

In late 1995, the National Solar Observatory and the USAF Phillips Lab group at SacPeak began the cooperative development of an active optics system for the VacuumTower Telescope (VTT). Although the immediate objective of this project is to providea system for sensing and correcting the slowly varying aberrations in the optical systemof the VTT, the system is also intended to provide a platform for further development ofa full atmospheric compensation system for use in solar imaging. A correlating 69-subaperture Shack-Hartmann wavefront sensor, capable of using solar granulation as itstarget, and a 97-actuator deformable mirror, manufactured by Xinetics, Inc., are the keycomponents of the new system. During March 1997, the control loop was closed for thefirst time at the VTT. The ability of the active optics system to improve the resolutionperformance of the VTT using both a small sunspot and granulation as the wavefrontsensing target was successfully demonstrated. The principal telescope aberrations in thistest were introduced by the uncooled entrance window of the VTT. We believe that thecorrected telescope was compensated to better than 1/10 wave by the active opticssystem during this test.

IV. DIVISION OPERATIONS

A. CTIO

Telescope Upgrades and Instrumentation

CTIO's program continues to focus on upgrading and instrumenting the telescopes so thatthey remain scientifically productive in an era of modern 4-m and 8-m apertures. The Gemini8-m project is well advanced on Cerro Pachon, and it will have a modern 4-m companion inthe SOAR telescope. These projects will be coming on-line within the next five years, and weanticipate that CTIO technical and scientific resources will be used extensively in the SOAR(and possibly Gemini) instrumentation and commissioning. The combination of SOAR andthe Blanco 4-m and their instruments will be configured as far as possible—through sharing

arrangements between the 4-m telescopes—as a complementary observing system in supportof work with Gemini.

1. 4-m Upgrades

A main focus in FY 1997 continued to be the performance and general maintainabilityof the Blanco 4-m telescope. The addition of active optics, image analyzer, and carefulthermal monitoring and controls over the past several years has been very successful,and delivered image performance has improved significantly.

The image analyzer has been in routine use at the Cass focus during the year, which hasallowed the active primary support system and careful collimation of the prime focusand secondaries to deliveroptical images as good as 0.52 arcsec. During FY 1997 a newset of temperature probes and associated control system has been designed, more thandoubling the database of thermal environmental information. Analysis of the dataproduced by the many temperature probes installed on the telescope and dome interiorhas indicated that heat sources in the dome and building interior are still significant;control and removal of these are being addressed. The primary mirror cooling system isrun for up to several hours each day to try to bring the mirror to within 0.5 degree of theestimated mean nighttime air temperature. The system is under computer control, andwe are experimenting with the algorithm so as to improve the accuracy of the night-timetemperature prediction. The capacity of the cooling system has proven to be marginalduring winter-time and we are investigating ways to improve this. An air extractionsystemwas installed to flush the primary mirror cell and chimney area duringobserving,which has also helped to maintain proper mirror temperature.

During FY 1997 effort has continued on studying and improving the servo system'sperformance. Initially this involved careful tuning of the existing servo system and theaddition of filters, feedback, andramps in theservo loop, all of which was accomplishedlast year. We have since identified and fixed some sources of flexure and error in theencoder/servo and are still in the evaluation stage of this work. We have also begun apilot project to replace the actual servo system, in order to provide a modern andmaintainable level of performance, using a Gemini-compatible servo controller.

Oneof our top-priority projects has been the implementation of tip-tilt with the new f/14secondary on the 4-mtelescope. The goal is to make our IR instrumentation compatiblewith the KPNO 4-m (f/15) and Gemini (f/16). The new secondary has been installedwith piezo-electric actuators in place; a fast guiding camera and software control systemhave been implemented. This gives CTIO the only major IR tip-tilt capability in thesouthern hemisphere. This is the logical extension of the program to improve theimaging capability of the telescope. The emphasis needs to be on the near IR (JHK)because this is where tip-tilt achieves the greatest proportional reductions in imagediameter for a 4-m telescope with good seeing. This will produce an importantimprovement in the performance of our near IR instrumentation.

This tip-tilt focus feeds the Cryogenic Optical Bench (COB), and the CTIO IRspectrometer, which has been converted to an f/14 system. Initial results areencouraging, although full system performance has been compromised by a variety ofminor issues, includingpoor weatherand variablesite seeing.

Balzer cyrocooler systems have been installed at the 4-m and in the La Serenalaboratory to support these and future IR instruments.

Major Instrumentation Efforts

A major feature of the program during the past year has been preparations for newinstruments which are due to arrive in 1998-1999. In collaboration with the Tucson IPGeffort, we are equipping the Blanco 4-m with:

•

•

the Cryogenic Optical Bench (COB) with a InSb array; this was installed inNovember 1996and has been in routine use this fiscal year;

• the NOAO 8K Mosaic CCD imager at prime focus (due January 1999);

• the Phoenix high-resolution IR spectrometer (nominally for July 1998); and

the Hydra/CTIO multi-fiber spectrograph (October 1998). Thus within 1.5 yearswe should have a 4-m telescope with excellent image quality over a small field atf/14, mainly for near IR imaging and spectroscopy. In the optical, the wide-fieldaspects are being emphasized with the Mosaic imager and Hydra spectrograph; thetelescope will be able to deliver good image quality over a 45 arcminute field atboth prime and Cass focus.

Work has started on the bench spectrograph in preparation for the Hydra system. Thisinvolves a change in collimator and camera/detector, to accommodate the slower f/ratioin the change from the prime focus to Cass and the larger number of fibers (from 48 to2 x 138) as Hydra replaces Argus as the fiber multiple-object spectrograph.

For the Blanco prime focus, we accomplished the commissioning and very successfulscientific use of an optical mosaic imager (the BTC, with 4K x 4K, thinned, SITeCCDs), an instrument provided by A. Tyson (Lucent Technologies) and G. Bernstein(U. of Michigan).

3. SOAR 4-m Telescope Project

As reported elsewhere (section V.E.) the initial project definition and scientificrequirements phase for the 4-m SOAR telescope have been almost completed, aninterim agreement has been signed, and a project manager and project scientist havebeen hired to begin the SOAR project. CTIO staff have, of course, been heavilyinvolved in the extensive studies, discussions, document preparation, and meetingsassociated with the preparatory phase of this project.

SOAR is a key component of the current long-range plan at AURA to set up a suite(Gemini South 8-m, SOAR 4-m, and refurbished Blanco 4-m telescopes) of largeaperture, general-user, southern-hemisphere, groundbased facilities for open competitiveaccess to the general research community. The plan is fully consistent with the NASdecadal review for the 1990s and the report of the McCray panel on the future ofNOAO. Discussions are currently underway with various US university andinternational groups with a view to constructing a set of 2.4-m telescopes in both

hemispheres as a means to cover the smaller-telescope end of the suite of general-usertelescopes.

4. CCD Implementation and ARCON Controller Development

Implementation of CCDs at the telescopes and the development of the ARCON CCDcontrollercontinued to be a central part of the optical instrumentation program this year.

A SITe 2048 x 2048 CCD (with four good amplifiers) was purchased, as a replacementfor the prime focus imager and echelle detector, which suffered a mysterious and fatalelectrical failure. Efforts are also being made to replace the STIS 2K x 2K CCD at theSchmidt, which also went out of service due to a mechanical failure in the dewar.

During FY 1997, major effort at CTIO has gone into supporting the ARCONs used inthe NOAO 8K Mosaic CCD Imager system on Kitt Peak; this integrated hardware andsoftware effort has resulted in a system that was first used for science in June 1997.Several engineers and scientists from CTIO have participated in engineering runs atKPNO.

We also intend to begin retrofitting the existing ARCONs on CTIO with the finalversions of three new controller electronics cards (Video, VTT, and ADC), which havebeen developed over the past years.

5. Existing Small General-User Telescopes on Cerro Tololo

CTIO's second-largest telescope, the 1.5-m, suffers from a poor thermal environmentand several optical problems with the secondary mirrors. In order to tackle this problem,more stable secondary mirror mounts have been designed, with encoders to permitreliable collimation runs. Ventilation doors for the 1.5-m dome have been installed, anda revised ventingand heat control system is being implemented in the building. An arrayof 32 doors with a total area of over 500 square feet have been installed in the segmentsaround the lower rim of the dome. A telescope control system (TCS) has been installedon the 1.5-m, which now shares the TCS software with the 4-m. The GUI/Guider systembeing developed on the 4-m will also be installed on the 1.5-m, permitting faster targetacquisition and support from extensive stellar databases for target selection.

6. New "Tenant" Installations and Upgrades

Installation of the building and dome for the 1.3-m 2MASS (South) telescope has beencompleted just below the GONG site on Cerro Tololo. Installation and commissioningof the telescope will begin later this year. More information about the 2MASS projectcan be found via: http://pegasus.phast.umass.edu/.

The Yale 1-m telescope was withdrawn from service for general users in early 1997becauseof a lack of adequate NSFfunding. A privateconsortium has been set up, led byYale University and including the Ohio State University, the University of Lisbon(Portugal), and NOAO. The consortium has so far been characterizing the telescopeperformance with a view to deciding on the upgrade paths to be followed. It is expectedthat the telescope will come back on line, for consortium use, sometime in 1998 and beoperated for an initial period of three years. Much of the research with this telescope

10

will focus on synoptic studies. Ohio State University will be providing a two-channelIR/optical imager, ANDYCAM, for this telescope. The University of Lisbon isproviding the funds for bare-bones operation of the facility. Roughly 9% of the time islikely to be available for NOAO users. NOAO's participation in the project consistsmainly of providing access to dormitory space and limited technical support. Additionalservices are provided to the consortium at cost.

An MOU has been signed with the United States Naval Observatory (USNO) to begin atwo-yearcampaign to secure astrometric CCD-based measurements and produce a high-density catalog of reference stars in the SouthernHemisphere between magnitudes 7 and16 with accuracies of ~ 20 mas at epoch. This will be done usinga specially developed8-inch astrographic lens and a commercial, thermo-electrically cooled CCD camera.This equipment will be attached to a remotely-controlled modified Boiler and Chivensmount originally used for a 24-inch telescope. Details of this project were presented bySteve Gauss, et al. at the Toronto AAS meeting. Further information can be found at:http://aries.usno.navy.mil/ad/ucac-s/.

This astrometric work will provide a dense set of positions ideally suited for initialcalibration of the Hydra-CTIO multifiber spectrograph (currently under construction inthe NOAO shops in Tucson) and of the near-simultaneous activity at the largest new all-sky survey telescope, 2MASS.

A robotic camera was installed on Cerro Tololo in January 1997 by a group led by JohnGaustad (Swarthmore College) and is expected to begin routine operation in September.Like the GONG station installed during the previous year, this new system is designedto be fully autonomous, only requiring intervention by CTIO staff at weekly intervals inorder to change data tapes. This robotic telescope will carry out an H-alpha survey ofthe entire southern sky with a resolution of 1 arcminute per pixel over a period ofapproximately two years. The resulting data will primarily be used for studies of thewarm ionized component of the galactic interstellar medium. However, the survey alsohas applications to cosmology since it provides a measure of spatial variations in themicrowave emission from galactic hydrogen—a possible complication for studies offluctuations in the cosmic microwave background.

Other

The Save-the-Bits (STB) software and dedicated exabyte drives have been installed onall CTIO telescopes and are in routine use with the ARCON CCD controllers and withthe Wildfire IR data systems.

Although Cerro Tololo and Cerro Pachon are still' very dark sites, CTIO has becomeincreasingly concerned with the growing threat of light pollution from neighboringcities and towns. Thus we are continuing our collaboration with local officials as well aswith private industry to ensure that future lighting installations are as "astronomer-friendly" as possible. This program has concentrated on several fronts, including publicinformation, consultations on street lighting installation in local towns, a regional light-pollution ordinance, and work with a newly-created national environmental commission.

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B. KPNO

The major focus of the programs at KPNO during this year were on improvements to theimage quality at the 4-m Mayall telescope; continued operation of the WIYN telescope; andthe commissioning of two major new instruments—a mosaic imager for optical work and ahigh resolution infrared spectrograph. This year also marked the end of NOAO's participationin the operation of the Burrell Schmidt telescope.

1. Image Quality Improvements

This year we continued to make substantial efforts to improve the delivered imagequality (DIQ) at the 4-m Mayall telescope. Nightly seeing measurements show that themedian DIQ is 1.1", considerably more than the 0.8" achieved by WIYN. What causesthis difference? Examination of the seeing data demonstrates that the Mayall imagequality is dominated by thermal effects in the 4-m dome, with optical aberrationsplaying a secondary role at present.

a. If the primary mirror is warmer than the ambient dome air, convection from theprimary quickly becomes the dominant effect on the DIQ; the images degrade by0.3" for every 1°C of temperature difference. (If the mirror is colder than ambientdome air, little effect is seen.) During the past year we implemented a coolingsystem, which blows refrigerated air on the primary during the day. This year wefinished the electronic controls for this system, which is now in daily use. InFY 1998 we plan to fine-tune the system and improve its cooling capacity.

b. If the air at the top of the dome is colder than at the bottom of the dome, large-scale convection occurs and the DIQ is significantly degraded. This year weimplemented a dome air mixing fan to move cold air from the floor chillers up tothe upper part of the dome in order to maintain a more isothermal environment.

c. Temperature differences between the dome air and outside air significantlydegrade the DIQ. The largest Kitt Peak project this year has been to implementdome vents at the 4-m. These vents will provide an additional 1600 ft2 of openarea. In a 10 mph wind, there will be between 100 and 300 flushes of the domeeach hour, depending upon the direction of the wind relative to the dome. Weexpect that this air exchange will alleviate many, if not all, of the thermalproblems within the dome.

In addition, careful attention is being paid to the telescope optics. Wavefront studies arenow used routinely to assure proper collimation. These studies suggest that even whenthe telescope is fully collimated, the DIQ is degraded by about 0.1" due to astigmatismand other lower-order aberrations, with the effects worse in some parts of the sky. InFY 1998, we are initiating an effort to provide active primary mirror support to removethis contributor to the DIQ.

2. WIYN Queue Observing Experiment

The WIYN Queue observing experiment completed its second year of operation in1997, which was the first year in which nearly the entire NOAO time allocation on the

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WIYN 3.5-m telescope was scheduled in a queue format. In this format, NOAO staffexecute TAC-approved observing programs and investigators do not come to themountain to do the work. Using this manner of scheduling, the observatory hopes tomaximize the scientific productivity of the 40% share of time that NOAO has on thetelescope. Programs are executed primarily on the basis of TAC grade and suitability ofobserving conditions during a particular night. The queue experiment allows for theimplementation of science programs that are difficult, if not impossible, to schedulewithin classical (investigator present) observing runs. Examples are synoptic programs,programs requiring less than one night to complete, and imaging projects requiring thebest possible seeing that the facility can provide. Queue scheduling also easily enablesthe mixing of spectroscopic and imaging programs during a night because the WIYNtelescope is equipped with two permanently mounted facility instruments (Hydra/MOSand CCD Imager) and has the capability of quickly switching between instrument ports.In addition, the queue experiment provides experience for the development ofscheduling strategies for the Gemini 8-m telescopes.

During the past two completed observing semesters, queue observing provided data for35 of 42 TAC-approved "long" programs (observing programs requiring more than 2hours of telescope time) and fully completed 16. There were 21 "short" programs ofwhich 13 were completed. Unfortunately, no data were obtained for 3 short programs.The fraction of requested observations actually completed for a program largely reflectsthe standing (TAC grade) of the program within the queue. For these two semesters 97nights were allocated to the WIYN queue program. Roughly 35% of this time was lostto weather and another 5% to technical problems. Scientific results from WIYN are justbeginning to appear in the refereed journals, with slightly more than half of the refereedscientific papers now in print dealing with data obtained through the NOAO queue.

A survey designed to evaluate the effectiveness of the WIYN queue program and theefficiency of its operation was sent to the entire NOAO WIYN user community (370astronomers) in early October 1997. Responses from this survey will be a major factorin deciding the future of the WIYN queue program.

WIYN

WIYN continues to operate routinely and remarkably effectively, given the small size ofthe operational support staff (6.5 FTE, including three operators for daytime andnighttime support of visiting astronomers). The overall efficiency of WIYN is 85%,with 9% of observing time lost to overhead and 6% lost to technical problems.Overhead at WIYN includes time for initializing the telescope and subsystems,acquiring objects and setting up the guiders, tuning the optics, focusing the telescope,configuring instruments, and reading out CCDs. Some of the overhead tasks have beenstreamlined for more efficient operation and other improvements are planned. The timelost to technical problems is dominated by computer and software reliability issues andefforts are in progress to improve both.

A two-year Improvement Project program was launched on 1 January 1997 whenspecial funding was obtained to provide enhanced staffing of approximately 2 FTE forthe two year period. The improvement program places emphasis on the safety aspects ofthe facility. Specific action items include enhancements to the WIYN safety programand policies, upgrades to the hardware limit systems on the telescope, improvements to

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the access to various subsystems for maintenance, and implementation of a softwaresystem to monitor all safety systems and to provide safe shutdown modes and betteralarming for the operators. Other improvements projects deal with telescopeperformance, reliability, and maintainability and include completion of the technicaldocumentation to facilitate maintenance.

4. KPNO Instrumentation Improvements

FY 1997 marked the year of commissioning for the CCD Mosaic Imager. TheKPNO/CTIO instrumentation group has produced an imager with 8096 x 8096 formatthat has an active imaging area of over 12 cm on a side. The imager is beingcommissioned with 2K x 4K three-side buttable engineering grade CCDs from Loral.Twenty thinned scientific grade CCDs have been ordered from SITE forNOAO througha consortium purchase with Carnegie. We will then have enough CCDS for two MosaicImagers, and a clone will be built for CTIO. Two of the CCDs have been delivered andare currently being evaluated and optimized. The Mosaic Imager has been available forshared-risk observing on KPNO telescopes since June 1997 and has been scheduled fora total of 50 nights through January 1998.

Phoenix, which is a high-resolution near-infrared spectrograph that operates over thespectral range 1-5 microns and uses two quadrants of an ALADDIN InSb array detector,has been commissioned and was used for 14 nights of science runs on the KPNO 2.1-mtelescope during the first semester of 1997. One of the highlights was a study of thechemical composition of Comet Hale-Bopp. The instrument is heavily scheduled onboth the 4-m Mayall and 2.1-m telescopes during the second semester of 1997. Work isin progress to address three outstanding issues: 1) the determination of the cause of theworse than expected image quality, which is thought to be due to the thermalcharacteristics of the grating and affects the S/N ratio; 2) spectrograph configurationspeed; and 3) a graphical user interface to simplify routine operation.

The installation of these instruments has required substantial modifications to thetelescopes to support the Mosaic at prime focus and to construct handling equipment forthis heavy instrument; to provide new wide-field correctors for the Mosaic at both the 4-m Mayall and 0.9-m telescopes; and to provide closed-cycle cooling at both the 2.1-mand 4-m telescopes for Phoenix.

5. Burrell-Schmidt

For nearly 20 years, KPNO shared operations and observing time at the Burrell-Schmidtwith Case Western Reserve University. The unique feature of this telescope is its widefield of view, and after the recent installation of a CCD imaging system, the demand forobserving time soared. However, KPNO concluded that because of its declining budgetit could no longer support its share of the operation, particularly since the advent of theMosaic Imager provides thesame wide-field capability with better sampling at the 0.9-mtelescope. Therefore, we have made arrangements to return operation of the telescope toCase Western, which has formed a consortium of astronomical institutions that willensure its continued use.

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NSO

1. Kitt Peak

a. McMath-Pierce Main Spectrograph Control

The purpose of the spectrograph control upgrade is to place the spectrographfunctions under computer control, allowing high-resolution and automatic controlof grating position. The computer will also allow automatic placement of thespectrograph grating in wavelength and angular coordinates in addition to thecurrent encoder coordinates. Added future benefits of the networked nature of the

control system are the possibility of remote observations, remote monitoring oflocal observations, and World Wide Web access to various instrumental functions.

To date, all the components of the upgrade have been purchased and received withthe exception of the new 19-bitgrating positionencoder. A mock-up of the gratingsystem has been constructed to allow for software development in the Tucson labwithout disturbing the current spectrograph operations.

A new hand paddle controller is being developed in conjunction with the Kitt PeakVacuum Telescope (KPVT) upgrade and will be used as the primary interface tothe main spectrograph until instruments with automatic control are developed. Thebasic software components have been completed or are near completion to allowbasic manual operation of the spectrograph with the new computer controlsinstalled.

Installation of the control hardware and interim hand paddle and software isscheduled for September 1997 with the completion of the project scheduled forOctober 1997. This project will yield significant improvements in the flexibilityand ease of use of the main spectrograph.

b. NIM-2 Near Infrared Magnetograph

The NIM-2 project is constructing an imaging vector magnetograph based on apiezoelectrically-tuned, servo-stabilized Fabry-Perot etalon. The existing NearInfrared Magnetograph maps the true magnetic field strength in the deep solarphotosphere, using the McMath-Pierce Telescope, the 13.7-m verticalspectrograph, a liquid crystal polarimeter, and an infrared array camera thatrecords two Zeeman-sensitive iron lines near 1565 nm. Using the same infraredcamera with an improved polarimeter and data system, NIM-2 will achieve bettertime resolution and geometric stability (because the field of view is imagedsimultaneously rather than built up by scanning) with little sacrifice in spectralresolution.

NIM-2 was ahead of schedule during FY 1996 but encountered difficulties duringFY 1997, mainly related to the optical design. All fabrication is now complete.After several engineering runs, a satisfactory protocol for optical alignment hasbeen established, and test magnetograms have been obtained. The main remainingtask is to identify and eliminate software bottlenecks that slow the system downfrom its nominal modulation speed of 10 Hz to about 3 Hz, introducing excess

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seeing noise into the magnetograms. The necessary programming resources areexpected to be available in the first or second quarter of FY 1998. The NIM-2project is partially supported by a grant from NASA.

c. Large-Format IR Array Camera

The McMath-Pierce facility offers capabilities that are unique in the world forinfrared solar observations: an unobstructed, all-reflecting light path (giving fullwavelength coverage with low thermal background) and large aperture (forangular resolution and photon flux). These capabilities cannot be fully exploitedwithout a state-of-the-art infraredarray detector at the focal plane.

The present detector is a commercial 256 x 256 InSb array from AmberEngineering, re-housed in a dewar from Infrared Laboratories. This system waschosen for low initial cost and 1-5 micron wavelength coverage. It has served wellbut is now becoming obsolete.

NSOplans to replace the Amber array with a state-of-the-art 1-5 micron camerabytaking advantage of NOAO's investment in the ALADDIN array developmentproject. The performance of an ALADDIN-based system will surpass the Ambersystem in every important respect (dark current, readout noise, quantumefficiency, and immunity from electronic interference); its 15-20 Hz frame rate iswell matched to the requirements of NIM and NIM-2.

During FY 1997, NSO committed funds for an ALADDIN controller to beconstructed by NOAO/TPG and delivered in late FY 1998. NSO continued toprepare for the ALADDIN era by hosting two runs at the McMath-Pierce with theALADDIN-based Phoenix cryogenic spectrometer, during which science-qualitydata were successfully obtained. The NSO infrared program proceeds on theassumption that NOAO will allocate one or more ALADDIN arrays to NSO fromthe yield of science-grade arrays.

d. Kitt Peak Vacuum Telescope Control Upgrade

The aim of this project is to upgrade the 23-year-old control and guiding systemsof the KPVT. Maintenance of these systems is becoming difficult since many ofthe components are no longer available. Performance problems also limit thequality and quantity of data from the focal plane instruments.

The overall goals of the project include better control of image guiding andscanning, reduction of unwanted image motion, replacement of obsoletecomputerized control systems, and computer control of the Littrow spectrograph.The overall upgrade plan is divided into small, stand-alone segments that provideprioritized, incremental improvements.

To date, new gear boxes and motor drivers for the drive system of the #2 mirrorhave been installed. These have greatly reduced the amount of backlash andimproved the reliability of these drives. Mounting and solenoid drives that willallow the #4 mirror to be rapidly tilted to reduce image motion have beeninstalled, tested, and tuned.

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The overall computer software and hardware architecture to be used to control thetelescope has been specified. A design for new sensors to replace existing limbguiders and supporting electronics is complete and breadboard construction andtesting is underway. The design activities are intended to be transferable to similarupgrades planned for the McMath-Pierce Telescope and the proposed SOLISproject.

New control and drive systems for the #1 and #2 mirror DC motor drives havebeen purchased and a design to interface them to the existing interconnect is inprocess.

New stepper motor drive amplifiers have been purchased to upgrade the existingguider platformsteppercontrols. The update is designed to eliminate the recurringproblems with platform mis-registration and stalling problems.

Sacramento Peak

a. Mark II Correlation Tracker

The development of the Mark II correlation tracker was completed in February1997. The system is now operational at the Vacuum Tower Telescope at Sac Peak.Relative to the Mark I CT, performance of the Mark II CT has been improved,with a higher servo bandwidth (60 Hz) and a capability to track low contrastgranulation images during moments of bad seeing. Cloning of the CT system toprovide tip/tilt correction at the McMath-Pierce telescope is being considered. TheBig Bear Solar Observatory has expressed interest in obtaining a copy of the MarkII CT.

b. Fast CCD Cameras

NSO/SP is working towards replacing the custom built MDA detector system withstate-of-the-art, large-format CCD detectors. A variety of detectors offeringdifferent capabilities have been requested by users. In addition to the MDAs, thefollowing cameras are now available at NSO/SP:

• Two Thomson IK x IK cameras with 10-bit resolution and a frame rate of upto 5 frames/sec. Typically these cameras are used for high-speed imaging andframe selection.

• A 2K x 2K 12-bit camera from Xedar Inc. in Boulder. The 2K x 2K camera

achieves a high frame rate of 2 frames/sec at a low noise level (30 e). TheXedar camera is a universal camera which has been used, for example, toimage the corona and for spectral imaging of large fields of view with highpixel resolution.

• A512x512 camera from Pixel Vision has been ordered and will be available

to users beginning January 1998. The camera features a back illuminated CCDchip from Site and offers high quantum efficiency throughout the visible

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spectrum, in particular at the blue end of the spectrum (CaK). The user canchoose between two readout rates. At the 850 kHz rate used to achieve highframe rates, the readout noise is < 30 e. At the slow 50 kHz readout rateprimarily used for low light level applications, the readout noise is < 9 e. Atleast one additional 512 x 512 camera will be added during FY 1998.

The data storage media is exabyte. However, DLT tape drives are now available toprovide high-speed recording capabilities (5 Mb/s) and large storage capacity (15Gb) for special applications.

Image Quality Improvement at the VTT

Wavefront sensor experiments revealed two major sources of optical aberrationsin the optics of the VTT: the entrance window and one of the two turret flats.

The thermal effects on the wavefront due to heating of the window have beengreatly reduced by an active cooling system that senses the gradient oftemperature, both across the face of the window and through its 4-cm thickness, bycombining the measurements from pairs of sensors on the outside and on thevacuum side of the window. Interferograms show that the window figure errorshave been reduced from several waves to a fraction of a wave, implying that thewindow temperature is now uniformly maintained to a few tenths of a degree. Theperformance of the VTT has been significantly improved by this; frame selectionprocedures now achieve diffraction-limited resolution.

The turret (elevation) flat was re-figured at Kodak and re-installed into the VTTduring September 1997. The overall optical performance of the VTT is currentlyevaluated using Shack-Hartmann wavefront sensor measurements.

Active Optics

The term active optics describes a low bandwidth system that corrects opticalaberrations, produced, for example, by telescope flexure or thermal stresses, andhence vary on relatively long time scales. The optical figure of modern largeaperture nighttime telescopes is controlled by active optics. Active control of thetelescope optics will also be required for the large solar telescope planned byNSO. The development of an active optics system that works on solar granulationis an important step toward demonstrating the technological feasibility of such atelescope. An active optics system can, of course, also compensate any residualoptical aberrations in the VTT. Furthermore, active optics can be considered anintermediate step toward an adaptive optics system, which in addition toinstrumental aberrations, will also correct atmospheric seeing. The three keycomponents of adaptive optics (as well as active optics) are the wavefront sensor,the reconstructor, and the adaptive mirror. Active optics operates with a lowbandwidth, on the order of 1 Hz or less, while atmospheric correction requires aclosed loop bandwidth of a few hundred Hertz. The active optics system willtherefore provide a convenient platform for further development of a fullatmospheric compensation system for use in solar imaging.

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The active optics system at NSO/SP consists of a correlating Shack-Hartmannwavefront sensor, capable of using solar granulation as its target, and a 97-actuatordeformable mirror, manufactured by Xinetics, Inc.

During March 1997, the control loop was closed for the first time at the VTT.Although active optics simulations and lab experiments were recently performedby the LEST group, to our knowledge this is the first real demonstration of solaractive optics using granulation as a target. The ability of the active optics systemto improve the resolution performance of the VTT, using both a small sunspotandgranulation as the wavefront sensing target, was successfully demonstrated. Thediagnostic output of the active mirror suggests that the corrected telescope wascompensated to better than 1/10X. by the active optics system during this test.

Adaptive Optics

Based on the progress we have made in several subareas of adaptive optics, we areconfident that we can build a solar adaptive optics system. A viable wavefrontsensor concept exists, the adaptive mirror technology is now commerciallyavailable, and we have learned to operate such an adaptive mirror within a shorttime with relatively little effort. From our active optics experiments we havegained experience at the integrated system level.

In principle, what is required to implement adaptive optics is to speed up the servoloop by several orders of magnitude. This involves parallel processing usingpowerful digital hardware. Due to tremendous advances in digital signalprocessing (DSP) technology during the last 5-10 years, it is now possible topurchase many, if not all, of the required hardware components off-the-shelf atreasonable cost. In fact, we have just completed development of a secondgeneration correlation tracker, which, unlike the first generation correlationtracker, was built entirely from commercial hardware components. A correlationtracker can be regarded as one channel of a SH-WFS based adaptive opticssystem. We have been able to successfully stabilize granulation images formed bysubapertures as small as 7 cm using the Mark II correlation tracker. During goodseeing conditions the residual image motion was 0".04 rms.

As the next step, we will implement a low order adaptive optics system that willcorrect on the order of 20 Zernike modes, with the idea that the system can beexpanded to a full-up adaptive optics system later. We are following the path thatwas taken by some nighttime adaptive optics projects which have proven to bequite successful (e.g., Roddier, et al., CHFT). The low order adaptive opticssystem will be capable of delivering diffraction-limited imaging in the visibleduring good seeing conditions, and in the infrared under most seeing conditions.The hardware design is near completion and we hope to have the developmentcompleted within the next two years.

Dual Fabry-Perot Filter

A dual Fabry-Perot (FP) filter system for visible wavelengths is underdevelopment at NSO/SP. The existing narrowband (< 20 mA) Fabry-Perot filter is

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combined with a newly purchased 60 mA passband FPand a set of narrow (3-4 A)blockers to provide a tunable narrow band filter with high transmission, capable oftuning at very fast speeds. In FY 1997 both FPs and the blockers werecharacterized. Parameters like the FPs passband, finesse and transmission weremeasured, and a tuning formula for the dual FP system was developed. InSeptember 1997, the first scans of the solar spectrum at 6302 A were performed,and narrow band filtergrams were recorded. The data are currently being analyzed.

g. Preparations for Eclipse 1998

NSO/SP, in collaboration with HAO, Rhodes College, and Lindau Institute, ispreparing three infrared experiments for the upcoming 26 Febuary 1998 eclipse inthe Caribbean. The first two experiments, to be conducted on board a CI30airplane, search for coronal spectral lines between 1 to 5 microns and circumsolardust out to 10 solar radii. Another groundbased experiment will measure thecoronal magnetic fields using Hanle effect.

h. Infrared Program

The NSO/SP maintains two near-IR camera systems which were developed byoutside collaborations with Michigan State University (MSU), Wyoming InfraredObservatory, and Haverford College. These cameras account for about 25% of theuser time allocated at the VTT and the Evans coronagraph and are used fordiffraction-limited imaging and high-precision (10"4) Stokes polarimetry for thestudy of various solar magnetic features.

A new IR camera for the 1-5 micron range that will be available year-round atNSO/SP is under development in collaboration with MSU and Starfire OpticalRange, Albuquerque. The development of the 1-5 micron camera system isprogressingon schedule. The electronics has been manufactured and is now beingtested.

i. Near-IR Imaging Vector Magnetograph

The USAF Phillips Laboratory, solar research group at NSO/Sacramento Peak hasdesigned a narrow-band tunable near-infrared filter which uses two tunable Fabry-Perot (FP) etalons and works between 1200 and 1700 nm with appropriateblockers. The FP etalons and their controllers have been purchased fromQueensgate. The order-sorting, broad-band FP has a full-width-at-half maximum(FWHM) pass band of 0.19 nm and a free spectral range (FSR) of 4.09 nm at1565 nm. The narrow FP has a FWHM pass band of 171 mA and FSR of about0.548 nm, at 1565 nm. A high transmission prefilter is available for use between1563 and 1566.5 nm. Initial tests of this filter system at the NSO/SP VacuumTower Telescope using a 128 x 128 InGaAs camera from Sensors Unlimited, theMichigan State 128 x 128 HgCdTe camera, and a specially constructed rotateablewave-plate and polarizer system have demonstrated the capabilities of this systemin making spectropolarimetric images in the spectral line, Fel 1564.85 nm. Testson the dual FP system at the VTT are in progress with the goal of evolving thesystem to a stand-alone vector magnetic field patrol instrument. Several vector

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magnetograms of sunspots were recorded recently. The instrument and itscomponents are available for use at the VTT on a shared-risk basis.

3. Digital Library Development

During FY 1997, NSO continued to populate its 300-disc CD-ROM jukebox with datafrom the FTS and KPVT. Currently, the jukebox holds a complete set of 38 discs ofnon-proprietary FTS transformed spectra, 13 discs of 512-channel magnetograph data,and 20 discs of spectromagnetograph data, for a total of about 50 GB of on-line storage.A high-resolution scanner has been obtained at NSO/SP to transfer the daily EvansFacility Ca K and H-Alpha spectroheliograms from film to CD.

Even in advance of the implementation of a user-friendly search engine, the jukebox isalready heavily used, with over 7000 files transferred in the period of 11 April 1996 to1 August 1997. With funding from the NSF Space Weather Program, there has beensubstantial progress in the development of a Web-based user interface and search tool.A prototype system for the KPVT data is now undergoing evaluation, and a system forthe FTS data is substantially complete. We anticipate releasing the system for generaluse by scientists and the public in early 1998.

D. USGP/ScOpe

The US Gemini Program (USGP) serves as a liaison between the International Gemini ProjectOffice (IGPO) and the US community. The Gemini Project is an international consortium tobuild two 8-meter telescopes, one on Mauna Kea, Hawaii, and one on Cerro Pachon, Chile, inwhich the US maintains a 50% share. The USGP was established in 1993 as a fourth division

of NOAO with a status which is on a par with Kitt Peak National Observatory, Cerro TololoInter-American Observatory, and the National Solar Observatory.

During the construction phase of the Gemini telescopes, the major activities of the USGPhave involved the procurement of the Gemini instruments assigned to the US and thediscussion of scientific issues between the Gemini project and the US astronomicalcommunity. In the operations phase, beginning shortly after the first Gemini telescope seesfirst light at the end of 1998, the USGP will have an additional role as the interface for USusers of the telescope. The recognition of this additional role and the resources needed tocarry it out have led to a restructuring of NOAO, with the USGP taking on responsibility forthese community interface activities in support of all the telescopes to which NOAO suppliesaccess. This increase in responsibility was accompanied by an increase in resources, begun inFY 1997. In FY 1998, the USGP will become an element of an enlarged division, known asScience Operations, or ScOpe. ScOpe will include more scientific staff as well as the NOAOunits which provide support for the community interface activities, including CentralComputing Services (of which IRAF is a part), the Tucson Photo Lab, and the TucsonLibrary. This report principally details Gemini-specific accomplishments, but also highlightssome of the areas in which the ScOpe staff has begun to turn its efforts.

A major part of the work of the USGP during the past year has been connected withprocurement of the Gemini instruments assigned to the United States. The United States isresponsible for three instruments, a near-IR (1-5 microns) imager, a near-IR spectrograph, anda mid-IR (8-30 microns) imager. The near-IR imager was assigned by the NSF to theUniversity of Hawaii; the USGP is responsible for the procurements of the other two

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instruments. The near-IR spectrograph was assigned to the NOAO instrumentation groupthrough a competitive selection in FY 1995. The mid-IR imager is still in the selectionprocess. At the request of the IGPO, the USGP has taken on the management of theseinstruments as the Gemini IR Instrument Program. This approach allows one group, theUSGP, to look out for interface issues, to identify areas of commonality among instruments,and to help to solve problems in areas of budget, schedule, and risk.

During FY 1997, the USGP carried out the procurement of the Gemini mid-IR imager in atwo-stage process. Two groups, at the University of Arizona and the University of Californiaat Irvine,.were awarded funding on the basis of a competitive selection to conduct conceptualdesign studies for this instrument. In addition, two groups, at the University of Florida andMauna KeaInfrared/JPL, agreed to perform studies at their own expense. The results of thesefour studies were presented to a panel of technical and scientific experts, and the comments ofthese experts were incorporated into the RFP for a second competitive selection of a supplierto producea final design and fabricate the instrument. Proposals in response to this RFP wereevaluated by an outside committee, and negotiations are now in progress with one of theproposers to build this instrument. We have been pleased to see that this approach hasfacilitated involvement in the Gemini instrumentation program by a number of USinstitutions.

In addition to these IR instruments, the United States has been asked to provide the detectorsand controllers for the Gemini optical instruments. The USGP has been monitoringdevelopment programs at a number of CCD vendors, and based on a review of proposals byan international committee of experts, a contract was negotiated with EEV to provide theoptical detectors. For the CCD controllers, the USGP faced a situation similar to that of theNear-IR Spectrograph, where both NOAO and university or commercial groups wished topropose for this work. Following the recommendations of the workshop held by AURA andNOAO in Albuquerque, we held an informal open meeting at which each potential supplierwas invited to present arguments supporting his approach and capabilities. A panel ofimpartial experts listened and questioned the proposers. As a result of this meeting, acollaboration was forged that involved hardware purchased from San Diego State Universityand software developed jointly at NOAO and the Royal Observatories in the UnitedKingdom.

After the selection of a supplier for each instrument is made, the USGP remains responsibleto the Gemini Project for seeing through the successful design, fabrication, and delivery ofeach US-allocated instrument. This activity includes day-to-day monitoring of progress byeach of the instrument suppliers, identifying concerns that have implications for cost,schedule, or risk, and helping the groups work out solutions to these concerns. DuringFY 1997, USGP personnel worked with the University of Hawaii near-IR imager group tohelp them develop a schedule and management plan for that instrument. The USGP alsoworked with groups at NOAO involved in the near-IR spectrograph, the near-IR arrays, andthe near-IR array controllers.

Following the USGP workshop in August 1996 on US interests in future instruments for theGemini telescopes, the international Gemini Project organized a similar workshop inAbingdon, England in January 1997. As in the US workshop, the discussion was focused onthe science that the communities will want to do with the Gemini telescopes and theinstruments that will be needed to carry out this science. The USGP organized and supportedthe participation by ten astronomers from US institutions in this international forum. The

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output from this meeting provides the scientific motivation for the suite of instruments thatmakes up the Gemini ongoing instrumentation program. Major elements of that program arean aggressive adaptive optics program, ultra-high resolution optical spectroscopy, and Near-IR spectroscopy with spatial multiplexing, eitherwith multiple slitlets or with an integral fieldfeed.

The USGP is responsible for keeping the community informed about Gemini's progress andfostering community support for Gemini. Displays are regularly presented at AAS meetings,and USGP staff contribute status information to both NOAO and Gemini newsletters. Inaddition, the USGP provides routine information about Gemini activities and milestones ofinterest to US astronomers and the public through electronic and printed media.

Another USGP responsibility is the monitoring of technical developments within the project.The US Gemini Project Scientist serves on the Gemini Science Committee (GSC) andrepresents there the views of the US scientific community. In addition to the GSC and projectscientist team teleconferences, formal input is contributed through participation in reviewsand working group meetings organized by the project. The USGP also solicits membership forUS participants in these reviews and meetings and organizes the US participation in the GSC.

In a similar way, the national project managers meet regularly to discuss procurements andother management issues. USGP staff take part in these discussions, and the US ProjectScientist represents US issues in these matters at semi-annual national project managersmeetings and the Gemini Director's review. During 1997, a new group, the Gemini instrumentforum, met immediately after each of the Director's reviews. This group, comprising thenational project scientists, national project managers, and Gemini personnel involved in thescientific instruments, is responsible for formulating and carrying out the Geminiinstrumentation program. Using input from the GSC and the Abingdon instrumentationworkshop and costing exercises carried out by the national project offices, this groupassembled a plan for ongoing programs. Early elements in this plan, which covers a ten yearperiod, include initial work on laser guide star adaptive optics for Gemini south and theaddition of a polarimetric capability for all the phase 1 instruments.

In a less formal sense, the USGP personnel interact frequently and directly with the GeminiProject to provide scientific and technical feedback, to identify scientific performance issuesand to help define technical solutions to meet the science requirements, to evaluateimplementation plans, and to participate in source selection for critical systems andcomponents.

The USGP has participated intensively in the development of a plan for the evolution ofresponsibilities in the operations phase of Gemini. It is clear that the international GeminiOffice will continue to depend on the national Gemini offices for a great deal of assistance ininteracting with the user communities of the partner countries. The national Gemini officeswill solicit proposals, perform technical evaluations, run national time allocation and users'committees, and will provide assistance to astronomers in writing Gemini proposals andreducing Gemini data. As a result of these considerations, the process of turning the USGPinto an organization with the capability to carry out these activities has begun, as mentionedat the start of this report. As ScOpe, this division has responsibility for:

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Providing information to the US astronomical community about all the capabilities availablethrough NOAO and how they can most effectively be used;

Unifying and coordinating the process by which telescope time proposals are submitted,processed, and reviewed;

Organizing a mechanism by which astronomers can obtain assistance in preparing observingproposals, preparing for observing runs, and reducingtheir data. This may include, in the caseof Gemini and the independent observatories that are supplying national access time inexchange for NSF funding for their instruments, identifying personnel who will become"instrument specialists" for these non-NOAO telescopes;

Providing software, where appropriate, for reduction of data for all instruments to whichNOAO provides access;

Developing concepts for, and perhaps implementing, an archive so that the community canmake the most effective use of the data that comes from all facilities to which NOAOprovides access;

Exploring concepts and implementations for alternative modes of operation such as remoteobserving and queue scheduling that may enable scientific investigations that are impracticalor difficult given the constraints of classical modes;

Developing and implementing a program of scientific outreach, through which a dialog withthe astronomical community about NOAO's mission can take place, including both thepresentation of that mission in order to foster community support and the solicitation of inputfrom the community to make NOAO more responsive to the community needs.

Although the definition of this program as a coherent effort is just beginning, two activitiesduring the past year should be reported as significant milestones.

• As NOAO moves into an era in which it provides community access to more telescopesthat it does not operate, it has been recognized that the community must see a simple,efficient interface to the suite of available facilities. A major element of this interface isthe process by which astronomers propose for telescope time. This realization, togetherwith the expectation that the number of proposals submitted each semester will risefrom 400 to 700 or 800, has led us to develop an efficient new database system formanagement of proposals and a new input mechanism for submitting proposals usingthe World-Wide Web.

Starting in September 1997, all applications for time at KPNO or CTIO were submittedusing the same LaTeX proposal form to the same electronic mail address. Applicationscould be submitted either by electronic mail or through the Web-based interface thatserves as a front end to the form. The interface allows the inclusion of text files and

figures on the proposer's computer, and it provides a convenient mechanism forproposers to work on a proposal over a period of time before submitting it. As proposalsare submitted, they are checked for completeness and formatting problems, and thenimported into the database. This whole process is remarkably efficient and over 400proposals were received, processed, and imported. This work was essentially complete

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by the afternoon of 1 October, the day after the deadline (midnight, 30 September).With the previous system, this activity took 3-5 days. Clearly, this mechanism is easilycapable of handling the much larger flux of proposals that NOAO will receive asadditional telescopes become available.

• A second event of note was the workshop on Supporting Capabilities for LargeTelescopes, held in Tucson on 26-28 September 1997. This workshop was an attempt toidentify and quantify, using a science-based approach, the facilities, software, andoperations modes that the entire US community will need in order to use very largetelescopes effectively. Approximately 50 astronomers, representing all the largetelescopes and telescope-building consortia as well as a substantial number frominstitutions that depend on publicly available facilities, met for three days to devisescientific programs aimed at answering important questions in eight areas ofastronomical research. The result was an understanding by all those present of thecrucial role that wide-field imaging capabilities will play in achieving our scientificaspirations. A number of surveys covering areas from a few square degrees tosignificant fractions of the sky and in a number of narrow and wide bands in the opticaland infrared were identified as essential. A broad consensus arose among participantsthat there was a need to find ways to facilitate many aspects of such surveys, includingdetector development, software pipelines, archives, and even the sociology of providingcommunity support for the effort needed. A report on the workshop will be written andwidely circulated as input to funding agencies and policy-making bodies.

E. NOAO Instrumentation

The mission of the Instrument Projects Group (IPG) is to develop and produce majorinstruments for the NOAO nighttime telescopes, including KPNO, CTIO, and Gemini. TheNOAO scientific staff conceives, directs, prioritizes, and evaluates the instrumentationprojects; the engineering managers are responsible for meeting schedule, budget, andperformance requirements. NOAO astronomers initiate new instrument projects in response touser requests, scientific staff interests, advances in technology, and announcements ofopportunity from the International Gemini Project.

Managing the instrumentation resources efficiently and in a manner that is satisfactory to bothsites is crucial to the success of our program. The Instrument Projects Advisory Committee(IPAC) provides scientific prioritization to the IPG. Its current members are Taft Armandroff(NOAO-Opt. Instr.), Todd Boroson (USGP), Dave De Young (KPNO), Jay Elias (GNIRSProject), Richard Green (NOAO-Chair), Brooke Gregory (CTIO), and Bob Schommer(CTIO). IPAC meets with the instrumentation engineering managers once a month to reviewpriorities, schedules, and budgets. They develop the scientific content of the long-range plan,on the basis of input from the users through the Users' Committee and personal contact, fromthe WTYN and SOAR partners, and from the Gemini advisory structure through the USGP.Every instrument under development has an instrument scientist from the NOAO scientificstaff. We believe that this arrangement is essential for successful development: eachinstrument must have an intellectual champion to see that the project meets its scientificperformance goals. IPAC provides a venue where the interests of each site are fairlyrepresented.

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Concurrent with the establishment of IPAC, we put into place a revised system of projectmanagement. It placed greater emphasis on initial design and planning and on overallaccountability and resource tracking. Neil Gaughan is the engineering projects manager. TheIPG reports to him, and he reports to Larry Daggert, the manager of ETS. IPAC works withNeil Gaughan and Larry Daggert to produce a detailed plan for the annual allocation oftechnical resources that is recommended to the Director and the NSF. It also organizes andparticipates in non-advocate design reviews for major projects. A system of review gatescontrols the rate at which resources are made available to a project, subject to the successfulcompletion of the previous review stage.

During FY 1997, our ongoing projects advanced, as described below.

1. CCD Mosaic Imager

The major instrument in commissioning during FY 1997 was the CCD Mosaic Imager,being deployed first at KPNO, then cloned for CTIO. IPG has produced an imager with8096 x 8096 format that has an active imaging area of over 12-cm on a side. It has alarge filter transport mechanism holding 14 six-inch filters and a pneumaticallycontrolled shutter mechanism that gives 1% timing accuracy in 1-second exposures. TheMosaic currently contains eight 2K x 4K three-side buttable CCDs from Loral, but theyare engineering grade. Thinned, scientific grade CCDs have been ordered for twoMosaic imagers, through a consortium purchase with Carnegie Observatories. By theend of FY 1997, we had received two of these CCDs, which are being evaluated andoptimized in our CCD lab. The CCD controller is a multiplexed quadruple version ofthe ARCON, developed and produced at CTIO. The first Mosaic Imager was madeavailable for shared risk observing on KPNO telescopes in June 1997 (three scienceprojects totaling nine nights in semester I; eight projects for 41 nights during semesterIT). The second Mosaic is scheduled for completion in FY 1999, with deployment atCTIO in the first half of the calendar year. The fabrication of mechanical parts forMosaic II was well advanced by the end of FY 1997.

2. Phoenix

Phoenix is a high-resolution near-infrared spectrograph operating from 1-5 microns,using two quadrants of an ALADDIN InSb array detector. Phoenix has beencommissioned and was used for 14 science runs on the KPNO 2.1-m telescope during1997 semester I. Some upgrade work has occurred in three areas: 1) understanding thecause of worse-than-expected image quality which affects delivered resolution andsignal-to-noise ratio; 2) spectrograph configuration speed; and 3) a graphical userinterface to simplify routine operation.

3. Hydra for CTIO

A new version of the Hydra multi-fiber positioner is being constructed for the CTIO 4-mtelescope. In the area of wide-field multi-fiber spectroscopy, the existing 4-mtelescopescomplement the capabilities of the Gemini telescopes. The present multi-fiberinstrument at CTIO is Argus, which was designed almost a decade ago. It is capable ofobserving 24 objects at a time, which puts it at a factor of four disadvantage comparedwith more modern instruments such as KPNO's Hydra. The new multi-fiber system isbeing built in Tucson and is based largely on the design of Hydra as it was converted

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from use at the Mayall to use at the WIYN. New motor controllers, a new gripper, andnew fiber cables are being produced for the system for CTIO, along with a new wide-field corrector with atmospheric dispersion compensating prisms. This instrument willbe located at the f/8 Ritchey-Chretien focus and will take advantage of the excellentimage quality by using fibers of smaller on-sky diameter than those of Argus. Deliveryand first commissioning activities are planned for October 1998. Good progress wasmade during FY 1997 on the fabrication of mechanical parts for Hydra/CTIO, opticsfabrication for the new Corrector/ADC, and electronics andsoftware development.

4. SQIID Upgrade

A high priority for the users, as expressed through the Users' Committee, is wide-fieldnear-IR imaging. The first realization of that capability will be in the upgrade of SQUD,the four-color near-IR imager. The 256x 256PtSi arrays will be upgraded to 512 squareInSb arrays with a customized NOAO/Gemini Controller. That instrument should beavailablefor shared risk user observations on KittPeak in fall semester 1998, contingenton the availability of the InSb arrays. The primary effort on this project during FY 1997was optical and mechanical design work to allow the incorporation of the new, largerarrays.

5. Gemini IR Array Controllers

The first instrument required for commissioning the first Gemini telescope is the Near-Infrared Imager (NIRI) under development at the University of Hawaii. NOAO isproducing for NIRI an upgraded version of the WILDFIRE controller that relies on thedigital signal processor produced by Datacube. That system will be delivered to Hawaiifor integration into the imager. Early results indicate that the array controller will havevery low noise and will meet NIRI's speed requirements. The design will serve as thebasis for controlling the arrays in the other near-infrared instruments that will be usedon Gemini, some of which will be provided by and shared with NOAO, such as COBand Phoenix. A software simulator and test hardware (a fully functional array mountwith cables and connectors) were delivered to Gemini in FY 1997. This delivery willallow Gemini and Hawaii to progress with interfacing the Gemini Near-Infrared Imagerto the NOAO controller. Final delivery of the controller and test dewar will occur inFY 1998.

6. Gemini Near-IR Spectrometer

The major instrument under production for Gemini is the Near-IR Spectrograph(GNIRS). This project is the largest IR instrument ever undertaken by NOAO. Thedewar will be 2 meters in length, and the instrument weighs some 2000 kg, includingelectronics. It will provide long-slit capabilities with a range of dispersions throughselectable gratings, covering the wavelength region from 0.9 to 5.5 microns at two pixelscales by means of four interchangeable cameras, which feed a single 1024 squareALADDIN-type InSb detector. The Gemini IRS project successfully passed itsPreliminary Design Review in October 1996. The instrument team spent the rest ofFY 1997 doing detailed design work in preparation for the Critical Design Review,scheduled for November 1997.

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7. High-Efficiency Spectrograph

Long-term studies are currently underway to define a new-generation moderate-resolution spectrograph for the 4-m telescopes. Scientific performance tradeoffs arebeing investigated to identify the most effective combination of field of view, spectraldispersion, and wavelength coverage. A key goal is to use the new generation of large-format CCDs with smaller slits and adequate pixel sampling, in order to exploit theexpected improvement in delivered image quality. In addition, the use of holographicvolume phase gratings, coupled with the highest performance anti-reflection coatings onall optical surfaces, should allow a significant increase in throughput. Conceptualoptical designs are under development.

In FY 1998, we will initiate design efforts for a wide-field infrared imager that will be usedon both the Mayall 4-m and a future, proposed 2.4-m imaging telescope. Other new activitieswill include work on a tip/tilt CCD imager for WIYN, a CCD MiniMosaic for WIYNresulting in a 4K x 4K format, and the integration of CCDs and CCD Controllers forGemini's GMOS instrument.

V. MAJOR PROJECTS

A. GONG

The Global Oscillation Network Group (GONG) is an international, community-based projectdesigned to conduct a detailed study of the internal structure and dynamics of the closest starby measuring resonating waves that penetrate throughout the solar interior. In order toovercome the limitations of observations imposed by the day-night cycle at a singleobservatory, GONG is operating a six-station network of extremely sensitive and stable solarvelocity mappers located around the Earth obtaining nearly continuous observations of the"five-minute" pressure oscillations. GONG is also operating a distributed data reduction andanalysis system to support the coordinated analysis of these data. GONG data are available toany qualified investigator whose proposal has been accepted; however, active membership ina GONG Scientific Team allows early access to the data and to the collaborative scientificanalysis that the Teams have already initiated.

A Scientific Advisory Committee continues to provide overall scientific guidance to theProject. In addition, a Data Management and Analysis Center Users' Committee providesimportant community input in the development of thiscritical partof the Project.

The stations are operating in close collaboration with the Big Bear Solar Observatory inCalifornia, the High Altitude Observatory's site on Mauna Loa in Hawaii, the LearmonthSolar Observatory in Western Australia, the Udaipur Solar Observatory in India, theObservatorio del Teide on Tenerife in the Canary Islands, and the Cerro Tololo Inter-American Observatory in Chile.

The Project's operations group maintains daily contact with the automatically operatinginstruments, largely through the internet. Daily site checks are performed by the Tucson-based staff via modem or internet, checking the current state of the instrument and reviewingany informational messages generated by the real-time system. Each instrument generates adatabase of 200 parameters recorded at one-minute intervals. These data are transmitted toTucson via the internet once a day for analysis by an automated system designed to detect

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performance anomalies and long-term trends. The instruments are also continuouslymonitored by scientists and technicians from the host observatories. When problems occur orrapid attention is required, the network operations duty respondercan be readily accessed viaphone, fax, or e-mail. Small technical teams are dispatched to each site every six to ninemonths to perform routine preventive maintenance.

The technical performance of the network continues to be excellent. The data duty cycle,including both weather and down-time, is currently about 87%. The best month recorded todate had a 94% fill factor and the worst has been 73%. Of all the possible images that couldbe obtained at the individual sites, fewer than 2% have been lost to equipment difficulties andmany of these were backed up by images taken at adjacent sites.

The operations group also continues to operate the Tucson prototype station as a "groundsimulator" for hardware and software modifications which will eventually propagate to thefield stations. It also serves as the primary source of "hot spares" and as a test bed for theproof of concept for the incorporation of a higher resolution camera into the existing stations.

The Data Management and Analysis Center continues to process the incoming data at a rateparallel to the more than one gigabyte per day of incoming field data. These data are reducedto 36-day time series (a "GONG month") of oscillation-mode coefficients and transformed toobtain the frequency spectrum for each mode. The data from these and other intermediatesteps are archived as defined data products in the Data Storage and Distribution System. Thetime between the data acquisition and the production of the month-long power spectra hasincreased to about 18 weeks. This has resulted in an increased tape storage efficiency and hasaccommodated an improvement in the registration of the images into heliographiccoordinates.

The distribution of archived data to the science community declined somewhat as comparedto the previous year's activity, but data transfers from the project's Web site increased.Requests for scientific data products are received by e-mail, the World Wide Web, and otherforms of communication; however, most data distributions are satisfied by internet transfers.Scientific data distributions during the past twelve months have averaged 31 thousand filesand 14 gigabytes per month. Data transfers from the Web site, primarily mode frequencytables, have averaged 0.7 gigabytes per month.

The data group also provides support to the in-house team and interested communitycontributors in an ongoing effort to improve understanding of the data themselves andenhance the quality of the data reduction processes. Several such enhancements have beendeveloped and incorporated into the current data pipeline during the past two years. Recently,the project embarked on a reprocessing campaign to produce a more homogeneous dataset.This effort is operating in parallel with the processing of newly acquired data and, in order tobetter satisfy the needs of the GONG scientific community, is proceeding in reverse orderbeginning with GONG month 16.

Recent helioseismic results unambiguously show that the solar p-mode oscillationfrequencies—and the internal solar structure—vary significantly during the solar cycle.Continuing GONG observations to cover a full 11-year solar cycle will add significantly toour understanding of stellar activity and its variability. Continuation of GONG operations willalso greatly improve our knowledge of the time-averaged properties of the solar interior.Replacing the existing 256 x 256 pixel GONG camera with a 1024 x 1024 camera will enable

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us to make higher resolution images of the local interior structures such as active regions andconvective patterns and to probe closer to the solar surface. Given the substantial investmentin establishing the network and its data management facilities, the incremental cost ofcontinued operations is highly leveraged.

The instrument group has been studying the feasibility of retrofitting a higher-resolution,square-pixel camera to the existing observing stations. A 1024 x 1024 camera model has beenidentified that has excellent characteristics. This camera could be installed with the existingoptical and telescope control systems. A seeing-effects study indicates that the current opticsand the image sampling rate are satisfactory for the larger format system. This new detectorwill provide spatial resolution comparable with the optical system resolution, thuseliminatingthe spatial aliasing in the current system as well as overcoming some inherent problems withthe current rectangular pixels. Increasing the detector scale would provide significantlyimproved helioseismic resolution in the near-surface regions. These areas are the home of theintense magnetic fields that seemto cause much of the moredramatic aspects of solar activity,extend all aspects of "local helioseismology" dramatically, and enable many non-helioseismic, diachronic solar measurements.

B. RISE/PSPT

The origin of the solar cycle has been a key astrophysical problem for many years. It receivedwider recognition with the recent suggestion that solar-cycle changes in luminosity may havea measurable influence on terrestrial conditions. A growing expectation that rapid progresscan be made against this problem is fueled by: 1) sensitive space observations of total solarirradiance changes; 2) new helioseismic inferences of sub-photospheric solar properties; and3) high-dynamic-range numerical simulations that allow the "multi-scale" complexity of thecycle problem to be explored. While this is good news, the bad news is that spatially resolved(full-disk) solarobservations with the differential (spatial) photometric accuracy of the space-based photometry do not exist. Such data are needed, both as an outer boundary condition forinterpreting helioseismic changes, and to interpret the measurable solar luminosity changes inthe context of physical models for the variability mechanism.

The Precision Solar Photometric Telescope (PSPT) project will develop and operate a smallnetwork of specialized instruments for obtaining high-spatial-resolution and high-photometric-accuracy solar surface photometry. These data will be obtained with a nearlycontinuous temporal resolution of about one hour and with spatial resolution only limited bythe 15-cm telescope aperture. Based on the GONG site survey data, the PSPT network canexpect to achieve occasional uninterrupted observing periods of half a solar rotation period(13 days) using a 3-site network.

To realize diffraction-limited resolution in the presence of seeing, the instrument uses a fasttip-tilt mirror in combination with digital frame-selection hardware. The design of theinstrument minimizes optical complexity and scattered light in the image plane. The 2K x 2KCCD camera electronics are beingdeveloped by a commercial vendor to provide an 8 Mpix/sreadout with approximately 30 electron read noise. The coated, deep-well detector will beused at four wavelengths between Call K at 393 nm out to approximately 700 nm.

The PSPT project is tightly constrained by budget and by community pressure to deploy theinstruments as soon as possible. Our development philosophy has been to depend heavily oncommercial vendors and to cultivate partnerships with other astronomical institutions. Since

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these instruments will produce data with a broad range of applications, the PSPT project hasseveral potential scientific and fiscal collaborations. To date, we have initiated partnershipswith two other institutions, Osservatorio Astronomico di Roma and the NCAR High AltitudeObservatory. Spanish astronomers at the LAC have also expressed an interest in a partnershipto operate a PSPT on Tenerife.

Several PSPT milestones have been achieved during the last year:

• The final (production model) PSPT telescope has been deployed at the OsservatorioAstronomico di Roma.

• An agreement with the HAO has been reached to collaboratively provide a RISE datadistribution center (primarily from the HAO).

• A new dome has been constructed at M. Loa and awaits the deployment of the next PSPT.

• Improvements to the flat-fielding algorithm were made that make it feasible to use withthe large format 2K x 2K camera data.

• The data-acquisition system and first version software control package have beensuccessfully implemented.

The PSPT programis part of the NSF SunRISE projectwhich is devoted to understanding themechanisms of solar luminosity variations. NSO began development in FY 1994 of a smallnetwork of photometric telescopes to measure solar surface brightness variations. Theinstruments are designed around a 15-cm objective, a 2K x 2K pixel CCD, and fast frame-selection electronics. Full-disk surface photometry with 0.1% per pixel accuracy with a one-hour cadence will be obtained.

Highlights from this year include: 1) deployment of the final PSPT instrument in Rome;2) completion of telescope dome at Mauna Loa; and 3) improvements in the calibration andflat-fielding algorithms.

The project is actively working to minimize development costs by seeking other scientificpartners interested in the PSPT hardware. For example, the Kiepenheuer Institut fiirSonnenphysik is currently using copies of our 2K x 2K camera for their observatory. NSOwill also share in the software development for the 2K x 2K Thomson camera system. Thenew camera will be useful for a broad range of high-spatial and photometric dynamic rangeproblems, and we expect the instrument/camera costs to decrease as additional partners areidentified.

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SOLIS

Improved long-term measurements of solar activity are key to any scientific strategy forunderstanding the solar cycle. NSO is already the acknowledged world leader in full-disksynoptic measurements. SOLIS, proposed to NSF in February 1996 as part of the "RenewingNOAO" proposal, represents a new generation of instruments that will form the core of theUS synopticcapability for the next twenty years and can serve as a prototype for a worldwidesynoptic network.

In order to relate measurements from GONG, RISE/PSPT, and other space- and groundbasedinstruments to the overall pattern of solar activity, it is necessary to make daily measurementsof magnetic and velocity fields, as well as chromospheric and coronal structure, with a stablesuite of well-calibrated instruments. The data provided by the SOLIS instruments will bedramatically improved in quality, quantity, and network availability compared with what iscurrently available. SOLIS will be cheaper to operate because of consolidation, automation,and modernization, and will replace NSO's existing synoptic facilities.

SOLIS was descopedat the request of NSF and currently includes three instrumentpackages:

1. Vector Spectromagnetograph: measures the strength and direction of the magnetic fieldin the photosphereover the full solar disk every 15 minutes, which is of prime importancefor understanding the dynamics of magnetic fields and their relation to chromospheric andcoronal structure (the present spectromagnetograph only measures the net magnetic fluxalong the line of sight, typically once a day);

2. Full Disk Patrol: delivers digital full-disk images of the Sun in various spectral lines athigh cadence (the present instruments typically deliver one image per day on film with avery limited selection of spectral lines);

3. Sun-as-a-star Precision Spectrometer: delivers very precise spectra of integratedsunlight over a substantial spectral range (current measurements are performed in a labor-intensive manner with a heterogeneous collection of older instruments using just a fewspectral lines).

During FY 1997, NSO established a Science Advisory Group for SOLIS whose members aredrawn from a wide range of solar research organizations. The group met three times and wasclosely consulted during the descopingexercise. A start-up plan was prepared to enable a faststart if funding becomes available. A close working relationship between NSO and HAO inrespect to the Vector Spectro-magnetograph component of SOLIS was initiated. Informalworking groups were established at both NSO sites. An international workshop with 80participants was held at NSO in September and focused on scientific issues that are the mainmotivation for SOLIS.

During FY 1998, NSO will continue to prepare for possible funding of SOLIS by consultingwith the external advisory group; by using its existing synoptic telescopes as testbeds forstate-of-the-art hardware and software concepts applicable to SOLIS; by continuing itsoutreach to the solar physics community through the SOLIS web page, the NSO Users'Committee (which has strongly endorsed SOLIS), AAS/SPD meetings, other fora such asNSO workshops and the community-based Solar Magnetism Initiative; and by continuing to

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pursue possible partnerships. Potential partners include NASA, the US Air Force, the NCARHigh Altitude Observatory, and the NOAA Space Environment Center.

D. Coronagraph and Low Emissivity Astronomical Reflector (CLEAR) Feasibility Study

Large solar telescopes areneeded to answer a number of important science issues. Among thedesired capabilities are: (1) high angular resolution needed to resolve the scales at which mostof the action takes place in solar magneto-hydrodynamics; (2) access to the infrared part ofthe solar spectrum, which is required to extend the range of physical conditions over whichthe solar atmosphere is studied; (3) accurate polarization observations needed to measuresolar magnetic fields; (4) high sensitivities, essential to study variations in these and othersolar conditions; and (5) low scattered light to observe magnetic fields and small-scalestructures in sunspots and in the solar corona. CLEAR is a concept which attempts tocombine these qualities in one telescope.

This year saw major progress in the development of the CLEAR project. A technical andbudgetary feasibility study of the CLEAR project is nearing completion. It has so far shownno "showstoppers." The study is focused on a 400 cm aperture, air-filled telescope with off-axis, low-scattered-light optics covering the entire 0.3 to 30 micron wavelength region. It hasa number of foci, some direct or folded f/30 Gregorian foci, others coude foci. The coude areacontains a large rotating instrument platform to allow removal of the image rotation. Thetechnical part of the study is expected to be completed in FY 1998. An interim study reporthas been published which will form the basis for the final report. It contains, in addition to thetechnical description of CLEAR, a costing as a function of telescope diameter (down to200 cm) and degree of scattered light control. Scattered light control at the coronagraphiclevel adds less than 10% to the cost.

Using solar scintillometry as a proxy measurement for site seeing assessment, we areconfirming earlier observations by Evershed and Leighton, who demonstrated the superiorityof lake sites for high-resolution observations. Observations at mountain locations (MaunaLoa, Kitt Peak, Sac Peak, and La Palma) show strong effects of the daytime build-up ofboundary layer seeing, limiting good seeing most of the time to the early morning. Big Bear,and four other lake sites tested, show on the other hand that the boundary layer seeing isabsent all day, resulting in all day long good seeing. As a result, their median seeing valuesare superior to that of mountain sites, approximating the best of the nighttime sites. Futuresite measurements will focus on improving the database, testing the effects of lake size, depthand wind direction, and testing the effects of water vapor and measurement of the skybrightness.

CLEAR deviates in a major way from existing "conventional" telescopes in that it does notuse a vacuum or helium-filled telescope environment. Both of the latter require a window infront of the telescope, blocking the infrared radiation and introducing scattered light. CLEARavoids that, at the cost, however, of potentially introducing interior seeing in the telescopeprimarily due to the heating of the primary mirror. We have constructed a 1/7 scale mock-upof CLEAR to test how well this internal seeing can be controlled by thermal control of thethin primary mirror and by airflow across the mirror. The mock-up is mounted on the largespar of the Evans Solar Facility on Sac Peak. In addition to testing the internal seeingbehavior of CLEAR, it will also test the effectiveness of dust control measures planned forCLEAR.

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Adaptive optics are an essential component of any large solar telescope. The NSO adaptiveoptics program being developed at the NSO/SP Vacuum Tower Telescope is, in that sense,critical to CLEAR as well. It is described in rV.C.2.

E. SOAR

The SOAR project has as its goal the construction of a 4-m class telescope in Chile. Partnersin this project, in addition to NOAO, are the Conselho Nacional de DesenvolvimentoCientifico e Tecnologico (CNPq), representing the astronomical communities of four states inBrazil, the University of North Carolinaat Chapel Hill (UNC), and MichiganState University(MSU).

Following an initial meeting in August 1996, the partners provided $200,000 to fund apreliminary design phase, which explored alternative configurations for the telescope andestablished the science requirements. This planning phase was evaluated by an ExternalReview Board in July 1997. The product of this design phase, together with therecommendations of the ERB, are now being used as the basis for the concept design phase,which will define the specific performance requirements for the SOAR Telescope, developthe concept for a telescope and associated support facilities that will meet these requirements,and definitively bound the cost of the fabrication and installation phases of the SOAR project.The concept design phase, which will be completed in the spring of 1998, will bring theSOAR Project to the point where the members of the SOAR consortium can review theoverall system design and the rationale for design selections and become confident that thecost estimate is accurate and valid. At that point, the partners will be asked to commit fullfunding for the construction phase.

The project team for SOAR is based in Tucson. The project manager is Tom Sebring, whowas project manager for the recently dedicated Hobby-Eberly Telescope, and the projectscientist is Gerald Cecil from the University of North Carolina.

The primaryscience requirement for the telescope is superb image quality—the goal is for thetelescope to degrade the image quality delivered by the atmosphere by no more than 0.18arcsec FWHM. The primary mirror will be a thin meniscus, which will have active supportand thermal control systems. The mount will be an alt-azimuth configuration with twoNasmyth ports for mounting instruments. Scattered light will be minimized through carefulattention to baffling, polishing, etc. The telescope will be located on Cerro Pachon, close tothe site selected for the Gemini telescope.

An English-language Web page for SOAR is being maintained at MSU and can be accessedthrough the NOAO home page.

VI. CENTRAL COMPUTER SERVICES

A. Tucson

The downtown Tucson computing facilities continue to evolve as older systems are replacedby newer, more cost-effective and easier-to-maintain systems. In particular, the machinesGemini (used as a Server on the Scientist Workstation Network) and Ursa (used for datareduction and analysis by staff and visitors) were significantly upgraded during FY 1997 (asthey were in FY 1996). Ursa is now a Sun Ultra-2 Model 2200 with two 200 MHz Ultra

34

SPARC processors, 512 MB of RAM memory and more than 70 GB of disk storage. Such apowerful machine is necessary to handle data analysis of frames from the NOAO Mosaicimager.

Also, several older disk drives on various CCS systems failed during the year and werereplaced by more reliable, and also larger, disks. Similarly, older laser printers were replacedby newer, more capable, printers.

The proliferation of desktop workstations, PCs and X-terminals to scientists' and engineers'offices has slowed as saturation is approached; however, many desktop systems wereupgraded to faster systems over the course of the year. The network infrastructure in thedowntown Tucson office building was upgraded with the addition of several special purposenetworks (including a Fast Ethernet subnet) and the continued implementation of switchedEtherneton the building backbone network. Upgrades to the dial-in networking facilities werealso undertaken.

In November, we switched the data connection from Tucson to Kitt Peak from a shared to adedicated T-l line. Thedata rate increased by a factor of 2.6 from 0.58 to 1.54 Mbps.

B. Mountain Programming Group

During FY 1997, we upgraded four programmers' workstations: two to Sparc 5s, one to anUltra-1/170, and one to a dual processor PC running Linux. We also moved all theprogrammers' workstations to their own subnet using Fast Ethernet. Finally, we acquired twoadditional copies of CapFast, a schematic capture program needed for support of Geminisoftware development.

C. CTIO - La Serena

The computer facilities in the La Serena offices serve the needs of diverse groups: visitingastronomers; the resident scientific staff; the engineers of the CTIO ETS; and the secretarialand administrative staff.

The desktop workstations used by several members of the scientific staff and those of the ETSprogrammers and EEs were replaced with modern mid-level machines at the beginning ofFY 1997. Additional machines for two new members of the scientific staff were also

purchased during the fiscal year. End of FY 1997 funds have been allocated for thereplacement of the PCs used by the mechanical engineers and draftsmen. During FY 1997 thenetwork of PCs used by the secretarial and administrative staff also underwent a substantialreorganization which has involved the replacement of most of the hardware. At the same time(and continuing into FY 1998) the operating system is being changed to WindowsNT, andcommercially available applications software, wherever possible identical to that in use inTucson, is being adopted.

End of FY 1997 funds have been allocated for the purchase of switched ethernet hardware,which will be used to replace the existing conventional ethernet backbone, leading toimproved speed and reliability. The new network hardware can also be easily upgraded toATM in the future.

35

D. CTIO - Communications

The implementation of a 64 Kbps terrestrial link between La Serena and Cerro CalanObservatory in Santiago (and thence to the Chilean Internet) was completed during FY 1997in partnership with Universidad de Chile. This allows for more efficient communicationbetween CTIO and the Chilean astronomical community and the other observatories in Chile.It also serves as a backup Internet connection for CTIO.

E. NSO-Sunspot

1. Upgraded 2 quad CPU servers from 50 MHz to 90 MHz CPUs.

2. Installed a WindowsNT server with software that will allow users to run Windowapplications from their UNIX stations. The plan is to move from Windowsl6 software,running on our Sun workstations through Wabi, to Windows32 software running on theWindowsNT server. Also several software packages that were supported under Solarisare being discontinued and only supported on the Windows platform.

3. Installed a DLT 7000 tape drive on our SUN Ultra Server. This drive provides theability to read DLT data tapes from our telescope sites and store the data on our SUNUltra Server.

4. Upgraded several old SUN IPC workstations to newer SUN workstations.

5. Installed an ethernet switch at the VTT telescope. The switch was installed to segregateethernet traffic between the bridge and table.

6. Upgraded/migrated software packages (AUTOCad and PADS) to the WindowsNTserver. This was in support of the ISOON project.

7. Purchased and installed a high-resolution scanner in support of the NSO data archivingproject. The scanner is being used to scan the NSO/SP archive of Ha and CaKphotographic images going back to 1960.This is a multi-year project.

VII. SCIENTIFIC STAFF

Hired

Date Name Position

10/01/96 C. Jason Pun Research Associate

10/01/96 Ivan Hubeny Associate Scientist

10/14/96 James Rhoads Research Associate

11/11/96 Frederic Baudin Research Associate

01/02/97 Charles Liu Research Associate

01/06/97 Louis Strous Research Associate

03/03/97 Stuart Jefferies Associate Scientist

04/24/97 John Worden Research Associate

05/05/97 Thomas Brown Research Associate

05/14/97 Robert Blum Assistant Astronomer

06/02/97 Patrice Bouchet Support Scientist08/11/97 JeffValenti Research Associate

36

Division

STIS

STIS

KPNO

NSO/GONG

STIS

NSO/SunspotNSO/SOI

NSO/Tucson

STIS

CTIO

CTIO

KPNO

Hired (continued)08/25/97 Harry Teplitz09/01/97 Rene Mendez

B. Completed EmploymentDate Name

10/18/96 Stephane Courteau12/31/96 Thomas Kinman

12/31/96 Richard Elston

01/14/97 Sydney D'Silva02/12/97 Yeming Gu02/21/97 Dave Silva

04/24/97 Frederic Baudin

08/14/97 Charles Liu

08/29/97 Ata Sarajedini09/12/97 Alejandro Clocchiatti

C. Changed StatusDate

10/01/96

12/31/96

01/06/97

Name

Olin EggenJack Baldwin

Hoasheng Lin

03/27/97 Nick Suntzeff

04/03/97 Thomas Rimmele

04/21/97

05/01/97

06/08/97

08/22/97

09/01/97

Richard Green

Mark PhillipsEdward AjharIan GatleyAlistair Walker

Research Associate STIS

CTIO-Chile Fellow CTIO

Position Division

Research Associate KPNO

Astronomer/Tenure KPNO

Associate Astronomer CTIO

Research Associate NSO/Tucson

Jr. Scientist NSO/SOI

Assistant Astronomer KPNO

Research Associate NSO/GONG

Research Associate STIS

Research Associate KPNO

Gemini Fellow CTIO

Position Division

Change from full-time to part-time status CTIO

Returned from Sabbatical Leave CTIO

Promotion from Research Associate

to Assistant Astronomer NSO/SunspotPromotion from Associate Astronomer/Tenure

to Astronomer/Tenure CTIO

Promotion from Assistant Astronomer

to Associate Astronomer NSO/SunspotOn sabbatical until 10/17/97 NOAO/KPNO

On sabbatical until 10/31/97 CTIO

Change from part-time to full-time status KPNO

On leave for one year KPNO

Sabbatical Leave CTIO

VIII. DIRECTOR'S OFFICE

The current management structure for NOAO consists of the following employees: Sidney Wolff,NOAO Director; Richard Green, KPNO Director/NOAO Deputy Director; Malcolm Smith, CTIODirector/NOAO Associate Director; Jacques Beckers, NSO Director/NOAO Associate Director;Todd Boroson, USGP Director/NOAO Associate Director; Mark Phillips, CTIO Assistant Director;Bruce Bohannan, KPNO Assistant Director; Robert Barnes, Assistant to the KPNO Director; GlenBlevins, Controller/Manager, Central Administrative Services; Larry Daggert, Manager,Engineering and Technical Services; John Dunlop, Manager, Central Facilities Operations; YvetteEstok, Manager, Public Information Office; Steve Grandi, Manager, Central Computer Services.

The NOAO Director is responsible for the overall operation of NOAO, which includes providingscientific leadership for NOAO, determining priorities, planning budgets, and allocating resources.The Director represents NOAO, and in particular, the four scientific divisions (CTIO, KPNO, NSO,and USGP) to AURA, NSF and the scientific community.

37

IX. STATISTICS

DuringFY 1997 the KPNOand CTIOdivisions of NOAOadopted a new database program to trackobserving proposals and programs scheduled on NOAO's nighttime telescopes. To simplify thetransition to the new system and to reduce the effort required long-term to provide statisticalinformation on the effectiveness of NOAO's nighttime telescopes, we are changing the reportingperiod for telescope statistics to coincide with the observing semesters at KPNO and CTIO. For theAnnual Report covering the period 1 October 1996through 31 September 1997, observingstatisticswill be included for the period 1 October 1996 through 31 July 1997. In subsequent years,observing statistics will be reported from 1 August through 31 July. Other information included inthe Annual Report will continue to cover the period from 1 October through 30 September.

A. CTIO

During the period of 1 October 1996 through 31 July 1997, a total 176 separate observingprograms involving 425 scientists (215 visitors, 210 collaborators) were carried out at CTIO.In the same period, 135 papers were published based on the use of Cerro Tololo facilities. Thenumber of nights CTIO scientific staff spent on CTIO during this period was 198. Thenumber of public visitors to CTIO during this same period is estimated to be 5,486.

Breakdown of CTIO Observational Statistics

(1) The figures in the following table reflect the number of observers/users physically present atthe Observatory and do not include multiple visits by a single observer/user. This table doesnot include NOAO staff. The total number of visits including multiple ones is 293. Visitingastronomers were assigned 90.2% of the observing time and the remaining 9.8% was assignedto the staff.

(2) Observers/UsersPhDs

Graduate Students

Technicians & Research Students

Total visitors

(3) Collaborators who were notphysically present

(4) Institutions represented by the above visits:

USA Institutions (50)

Arizona State U.

AT&T Bell Labs.

Brigham Young U.California Inst, of TechnologyCarnegie Inst, of WashingtonCase Western Reserve U.

Columbia U.

Cornell U.

Gemini Project OfficeHarvard-Smithsonian Ctr. for Astrophys.Johns Hopkins U.

US Latin A. Foreisn Total

95 18 39 152

34 4 12 50

1 10 2 13

130 32 53 215

123 9 78 210

38

Las Campanas Obs.Lawrence Livermore Nat. Lab.

Los Alamos Nat. Lab.

Louisiana State U.

Massachusetts Inst, of Tech.

Middlebury CollegeMiddle Tenn. State U.

Millikin U.

NASA Ames

NASA Goddard

New Mexico State U.

Northern Arizona U.

Ohio State U.

Pennsylvania State U.Pomona CollegePrinceton U.

Purdue U.

Rutgers U.Space Telescope Science InstituteState U. of New York

U. of Alabama

U. of Arizona

U. of California, BerkeleyU. of California, Sta. CruzU. of Colorado

Latin American Institutions (12)

Centro Estudios Cientificos, ChileFacultad de Ciencias, UruguayPontificia U. Catolica de Chile

Obs. Astron., ArgentinaObs. Felix Aguilar, ArgentinaObs. Nacional, Brazil

Foreign Institutions (31)

Anglo-Australian Obs., AustraliaDominion Astrophys. Obs., CanadaEuropean Southern Obs., ChileEuropean Southern Obs., GermanyEuropean Space Agency, The NetherlandsKapteyn Astron. Inst., The NetherlandsLeicester U., UK

Leiden Obs., The Netherlands

Max-Planck Inst., GermanyMt. Stromlo & Siding Spring Obs., AustraliaMullard Radio Astron. Obs., UKNat. Central U., Taiwan

Oss. Astron. di Capodimonti, ItalyOss. Astron. di Roma, ItalyObs. de Paris-Meudon, France

B. KPNO

U. of Florida

U. of Illinois

U. of Kansas

U. of MarylandU. of MichiganU. of Missouri

U. of Nevada

U. of North Carolina

U. of Oklahoma

U. of Texas at Austin

U. of WashingtonUS Naval ObservatoryVanderbilt U.

Yale U.

U. de Sao Paulo, BrazilU. de Chile

U. de Concepcion, ChileU. de La Serena, ChileU. Federal Rio Grande do Sul, BrazilU. Nacional de Cordoba, Argentina

Royal Greenwich Obs., UKSouth African Astron. Obs., South AfricaSternberg Astron. Institute, RussiaU. of Cambridge, UKU. of Central Lancashire, UKU. of Durham, UK

U. of Edinburgh, UKU. of Lisbon, PortugalU. of Montreal, Canada

U. of Tokyo, JapanU. of Toronto, CanadaU. of Victoria, Canada

U. Laval, Canada

Warsaw U., PolandYonsei U. Obs., Korea

York U., Canada

During the period 1 October 1996 through 31 July 1997, a total of 259 observing programswere carried out on NOAO telescopes on Kitt Peak. During the same period, 265 papers werepublished by staff and users of KPNO facilities. Associated with these programs were 532individual scientists, and 40 programs were identified as graduate theses. These programsbrought 409 scientific visitors to Kitt Peak, including 267 Ph.D. astronomers, 100 graduatestudents, and 42 others, with an additional 88 visits by KPNO scientific staff.

39

Astronomers using Kitt Peak telescopes in this period represented 79 US institutions and 28foreign institutions. The top five represented are:

1) Harvard Smithsonian Center for Astrophysics (16);2) University of Arizona (15) and Space Telescope Science Institute (15);3) NASA Goddard Space Flight Center (12);4) Pennsylvania State University (11);5) Ohio State University (10) and University of Colorado (10).

The number of public visitors to Kitt Peak in this period is estimated to be 50,000. Thisnumber is based on the recorded number of visitors participating in four daily public tours,the recorded number of visitors involved in filming, media, or special tour requests, and anestimated number of visitors who took self-guided tours at Kitt Peak.

Observers/Users

PhDs

Graduate Students

Technicians & Research Students

Total Visitors

Institutions represented by the above visits

C. NSO

US .Foreien Total

229 38 267

93 7 100

41 1 42

363 46 409

79 28 107

Duringthe periodof 1October 1996 through 31 July 1997, a total of 172 observing programs,involving 109 individual scientific visitors and 30 staff were carried out at NSO facilities.During the same period, 58 papers were published by 23 staff and 9 visitors-in-residence.Astronomers using NSO facilities during this period represented 28 US institutions and 17foreign institutions. Visiting astronomers were assigned 22% of the scheduled telescope timeand the remaining 78% was assigned to the staff.

During the reporting period a total of 633 outside users from 1619 institutions accessed themain NSO/Tucson data archive and distribution area a total of 15,208 times. A total of 20,625data files were transferred during these accesses. In addition, 23 distributions per observingday are made automatically to outside users, adding approximately 5500distributions per yearfor a total of over 26,000 data distributions annually to about 650 users. During this sametime period, NSO web pages were accessed by outside users a total of 47,798 times. Note thatthese statistics are for NSO/Tucson only.

During the reporting period a total of 11,424 scientific data files were transferred viaanonymous ftp from NSO/Sac Peak.

Observers/Users

PhDs

Graduate Students

Undergraduate StudentsTechnicians

Total Visitors 119 28 147

Institutions represented by the above visits

40

US Foreien Total

99 27 126

5 1 6

2 0 2

13 0 13

28 17 45

D. NOAO Tucson Headquarters BuildingStatistics

During the period 1October 1996 through 31 July 1997, a total of 1,533 visitors signed in atthe NOAO Tucson headquarters building.

41

APPENDIX A

National Optical Astronomy ObservatoriesOctober 1996 through September 1997 Technical Reports

The following papers were published by CCS personnel:

Bell, D.J. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.371, "Filtering KPNO LaTeX Observing Proposalswith Perl"

Davis, L.E. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.85, "CENTERFJT: A Centering AlgorithmLibrary for IRAF"

Fitzpatrick, M., Tody, D. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.310, "Automatic Mirroring of theIRAF FTP and WWW Archives"

Seaman, R., von Hippel, T. 1997, ASPConf. 125, ed. G. Hunt (ASP), p. 306, "WIYN Data Distributionand Archiving"

Seaman, R., Pilachowski, C, Barden, S. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.190,"Asteroseismology-Observing for a SONG"

Tody, D. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.451, "The Data Handling System for the NOAOMosaic"

Valdes, F. 1997, Conf. 125, ed. G. Hunt (ASP), p.459, "Data Format for the NOAO Mosaic"

Valdes, F. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.455, "IRAF Data Reduction Software for theNOAO Mosaic"

The following papers were published by ETS personnel:

Fowler, A., et al. 1997, SPIE, 2816, p.150, "ALADDIN, The 1024x1024 InSb Array: Design,Description, and Results"

Vaughnn, D. 1997, SPIE, 2864, p.429, "Identification and Analyses of Phosphorescent Materials for Usein Optical Systems and Instrumentation"

Vaughnn, D. 1997, SPIE, 2864, p.416, "The Electrostatic Application of Black FLocking for ReducingGrazing Incidence Reflections"

Vukobratovich, D. 1997, Handbook of Optomechanical Engineering, ed. A. Ahmad (CRC Press), p.45,"Chapter 2: Optomechanical Design Principles"

Vukobratovich, D. 1997, Handbook of Optomechanical Engineering, ed. A. Ahmad (CRC Press), p.lll,"Chapter 5: Lightweight Mirror Design"

West, S.C., et al. 1997, SPIE, 2871, p.74, "Progress at the Vatican Advanced Technology Telescope"

A-l

APPENDIX B

Cerro Tololo Inter-American ObservatoryOctober 1996 through September 1997 Publications List

Baird, S.R. 1996, AJ, 112, p. 2132, "RRLyrae Star Metallicites from Caby Photometry"

Baldwin, J.A. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 80, "BroadEmission Lines in Active Galactic Nuclei"

Barrado, D., et al. 1997, ApJ, 475, p. 313, "The Age of Gliese 879 and Fomalhaut"

Bechtold, J., et al. 1997, ApJ, 477,L29, "Ha Imaging of theCandidate Protogalaxy MS 1512-cB58"

Bechtold, J., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 122, "IRSpectroscopy of High-Redshift Quasars"

Bergeron, P., Ruiz, M.T., Leggett, S.K. 1997, ApJS, 108, p. 339, "The Chemical Evolution of CoolWhite Dwarfs and the Age of the Local Galactic Disk"

Berlind, A.A., et al. 1997, AJ, 114, p. 107, "The Extinction Lawin an Occulting Galaxy"

Blum, R. D., Sellgren, K., DePoy, D.L. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 277, "Really CoolStars at the Galactic Center"

Blum, R.D., Sellgren, K., DePoy, D.L. 1996, AJ, 112, p. 1988, "ReallyCool Stars at the Galactic Center"

Blum, R.D., Sellgren, K., DePoy, D.L. 1996, ApJ, 470, p. 864, "JHKL Photometry and the K-BandLuminosity Function at the Galactic Center"

Brandner, W., et al. 1997, ApJ, 475, L45, "Ring Nebula and Bipolar Outflows Associated with the B1.5Supergiant Sher 25 in NGC 3603"

Briley, M.M., et al. 1996, Nature, 383, p. 604, "Sodium Abundance Variations in Main-Sequence Starsof the Globular Cluster 47 Tucanae"

Brown,J.A., et al. 1996,AJ, 112, p. 1551, "Chemical Abundances in the Outer Disk Clusters Tombaugh2, Melotte 71, and NGC 2112"

Brown, J.A., Wallerstein, G., Zucker, D. 1997, AJ, 114, p. 180, "High-Resolution CCD Spectra of Starsin Globular Clusters. IX. The 'Young' Clusters Ruprecht 106 and PAL 12"

Buta, R., Combes, F. 1996, Fund. Cosmic Physics, 17, p. 95, "Galactic Rings"

Caldwell, N., Rose J.A. 1997, AJ, 113, p. 492, "The Butcher-Oemler Effect at Low Redshift:Spectroscopy of Five Nearby Clusters of Galaxies"

Cellone, S.A., Forte, J.C. 1997, AJ, 113, p. 1239, "The Peculiar Morphology of the Irregular GalaxyNGC 1427A"

B-l

Chu, You-Hua 1997, AJ, 113, p. 1815, "Supernova Remnants in OB Associations"

Chu, You-Hua, et al. 1997, PASP, 109, p. 554, "Uncovering a Supernova Remnant Hidden Near LMCX-l"

Clocchiatti, A., et al. 1997, ApJ, 483, p. 675, "SN 1983V in NGC 1365 and the Nature of StrippedEnvelope Core-Collapse Supernovae"

Costa, E., Frogel, J.A. 1996, AJ, 112, p. 2607, "Carbon Stars in the Large Magellanic Cloud:Luminosities, Colors, and Implications for the History of Star Formation"

Cowley, A.P., et al. 1997, PASP, 109, p. 21, "Magellanic Cloud X-ray Sources Observed with ROSAT"

Craig, N., et al. 1997, AJ, 114, p. 244, "Extreme Ultraviolet Explorer Optical Identification Campaign.III. A Southern Hemisphere Sample of Active Late-Type Stars and White Dwarfs"

Crowther, P.A., Bohannan, B. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D.Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 437, "On the Nature of Olafpe Stars"

Dahlem, M., et al. 1997, A&A, 320, p. 731, "Evidencefor a New "Superwind" Galaxy - NGC 4666"

Dale, D.A., et al. 1997, AJ, 114, p. 455, "Seeking the Local Convergence Depth. I. Tully-FisherObservations of the Clusters A168, A397, A1228, and A1983"

De Carvalho, R.R., et al. 1997, ApJS, 110, p. 1, "Redshift Survey of Galaxies Around a Selected Sampleof Compact Groups"

De La Reza, R., et al. 1997, ApJ, 482, L77, "On A Rapid Lithium Enrichment and Depletion of K GiantStars"

De Mello, D. F., Infante, L., Menanteau, F. 1997, ApJS, 108, p. 99 "A Catalog of Faint InteractingGalaxies in Pairs and Groups"

De Mello, D.F., et al. 1997, ApJS, 110, p. 227, "A Catalog of Faint Interacting Galaxies in Pairs andGroups. II."

De Mello, D. F., Infante, L., Menanteau, F. 1997, ASP Conf. 114, ed. S.M. Viegas, R. Gruenwald, R.R.de Carvalho (ASP), p. Ill, "Faint Interacting Galaxies in Pairsand Groups"

Due, P.-A., Mirabel, I.F., Maza, J. 1997, A&AS, 124, p. 533, "Southern Ultraluminous Infrared Galaxies:An Optical and Infrared Database"

Eenens, P.R.J., Piceno, A., Morris, P., Tapia, M. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M.Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 219, "On the InfraredSpectral Morphology of Wolf-Rayet WN Subtypes"

Eggen, O.J. 1996, AJ, 112, p. 1595, "Star Streams and Galactic Structure"

Eggen, O.J. 1996, AJ, 112, p. 2661, "The Ross 451 Group of Halo Stars"

B-2

Eggen, O.J. 1997, AJ, 114, p. 825, "The Abundance of CN, Calcium and Heavy Elements in HighVelocity Stars"

Ferguson, A.M.N., Wyse, R.F.G., Gallagher, J.S. 1996, AJ, 112, p. 2567, "The Spectacular IonizedInterstellar Medium of NGC 55"

Fischer, P., Tyson, J.A. 1997, AJ, 114, p. 14, "The Mass Distribution of the Most Luminous X-rayCluster RXJ 1347.5-1145 from Gravitational Lensing"

Fry, A.M., Carney, B.W. 1997, AJ, 113, p. 1073, "Chemical Abundances of Galactic Cepheid Variablesthat Calibrate the P-L Relation"

Geisler, D., Claria, J.J., Minniti, D. 1997, PASP, 109, p. 799, "Washington Photometry of Globular-Cluster Giants: Ten Intermediate-MetallicityClusters"

Ghez, A.M., et al. 1997, ApJ, 481, p. 378, "The Multiplicity of Pre-Main-Sequence Stars in SouthernStar-Forming Regions"

Giovanelli, R., et al. 1997, AJ, 113, p. 22, "The I Band Tully-Fisher Relation for Cluster Galaxies: DataPresentation"

Gnidica, M.A., Freeman, K.C. 1997, ASP Conf. 116, ed. M. Arnaboldi, G.S. DaCosta, P. Saha (ASP), p.54, "Dynamics of the Outer Halos of Ellipticals"

Goswami, A., et al. 1997, PASP, 109, p. 270, "The Spectrum of the Cool R Coronae Borealis Variable SApodis in a Deep Decline"

Gutierrez-Moreno, A., Moreno, H. 1996, PASP, 108, p. 972, "Spectroscopic Observations of Some D-Type Symbiotic Stars"

Gutierrez-Moreno, A., Moreno, H., Feibelman, W.A. 1997, ApJ, 485, p. 359, "Ultraviolet and OpticalObservations of Hen 1213, Hen 1341, and Hen 1761"

Hamuy, M., et al. 1996, AJ, 112, p. 2391, "The Absolute Luminosities of the Calan/Tololo Type laSupernovae"

Hamuy, M., et al. 1996, AJ, 112, p. 2398, "The Hubble Diagram of The Calan/Tololo Type laSupernovae and the Value of H0"

Hamuy, M., et al. 1996, AJ, 112, p. 2438, "The Morphology of Type la Supernovae Light Curves"

Hamuy, M., et al. 1996, AJ, 112, p. 2408, "BVRI Light Curves for 29 Type la Supernovae"

Hawley, S.L., Gizis, J.E., Reid, I.N. 1996, AJ, 112, p. 2799, "The Palomar/MSU Nearby StarSpectroscopic Survey. II. The Southern M Dwarfs and Investigation of Magnetic Activity"

Henry, TJ., et al. 1997, AJ, 114, p. 388, "The Solar Neighborhood. IV. Discovery of the TwentiethNearest Star System"

B-3

Higdon, J.L., Wallin, J.F. 1997, ApJ, 474, p. 686, "Wheels of Fire. m. Massive Star Formation in the'Double-Ringed' Ring Galaxy AM 0644-741"

Hoflich, P., et al. 1996, ApJ, 472, L81, "Maximum Brightness and Postmaximum Decline of LightCurves of Type Supernovae la: A Comparison of Theory and Observations"

Hoopes, C.G., Walterbos, R.A.M., Greenawalt, B.E. 1996, AJ, 112, p. 1429, "Diffuse Ionized Gas inThree Sculptor Group Galaxies"

Horner, D.J., Lada, E.A., Lada, C.J. 1997, AJ, 113, p. 1788, "A Near-Infrared Imaging Survey of NGC2282"

Hughes, J., Wallerstein, G. 1997, PASP, 109, p. 274, "Stars Above the Red Horizontal Branch in M15"

Hunter, D.A., Gallagher m, J.S. 1997, ApJ, 475, p. 65, "An Emission-Line Study of Supergiant IonizedFilaments in Irregular Galaxies"

Ibata, R.A., et al. 1997, AJ, 113, p. 634, "The Kinematics, Orbit, and Survival of the Sagittarius DwarfSpheroidal Galaxy"

Infante, L., De Mello, D.F., Menanteau, F. 1996, ApJ, 469, L85, "Strong Clustering of Faint Galaxies atSmall Angular Scales"

Jewitt, D., Luu, J., Chen, J. 1996, AJ, 112, p. 1225, "The Mauna Kea-Cerro Tololo (MKCT) KuiperBeltand Centaur Survey"

Kaluzny, J. 1996, A&AS, 120, p. 83, "CCD Photometry of Variable Stars in the Globular Cluster NGC288"

Kaluzny, J. 1997, A&AS, 122, p. 1, "CCD Photometry of Variable Stars in the Field of the GlobularCluster NGC 6397"

Kassis, M., et al. 1997, AJ, 113,p. 1723, "Deep CCD Photometry of Old Open Clusters"

Kastner, J.H., et al. 1996, ApJ, 462, p. 777, "H2 Emission from Planetary Nebulae: Signpost of BipolarStructure"

King, J.R., Deliyannis, C.P., Boesgaard, A.M. 1997, ApJ, 478, p. 778, "The 9Be Abundances of aCentauri A and B and the Sun: Implications for Stellar Evolutionand Mixing"

Kirkpatrick, J.D., Henry, T., Irwin, M.J. 1997, AJ, 113, p. 1421, "Ultra-Cool M Dwarfs Discovered byQSO Surveys. I. The APM Objects"

Korista, K., et al. 1997, ApJS, 108, p. 401 "An Atlas of Computed Equivalent Widths of Quasar BroadEmission Lines"

Kozhurina-Platais, V., et al. 1997, AJ, 113, p. 1045, "The Age of NGC 3680 and a Test of ConvectiveOvershoot"

B-4

Kuhn, J.R., et al. 1996, ApJ, 469, L93, "Tidal Disruption and Tails From the Carina Dwarf SpheroidalGalaxy"

Lamontagne, R., et al. 1996, AJ, 112, p. 2227, "Photometric Determination of Orbital Inclinations andMass Loss Rates for Wolf-Rayet Stars in WR+O Binaries"

Layden, A.C. 1997, PASP, 109, p. 524, "Light Curves for 40 Field RRLyrae Variables"

Lehnert, M.D., Heckman, T.M. 1996, ApJ, 472, p. 546, "The Nature of Starburst Galaxies"

Leitherer, C, et al. 1996, PASP, 108, p. 996, "A Database for Galaxy Evolution Modeling"

Lennon, D.J., et al. 1997, ASP Conf. 120, ed. A. Nota, H.J.F.L.M. Lamers (ASP), p. 90, "Luminous BlueSupergiants in the LMC"

Marston, A.P. 1997, ApJ, 475, p. 188, "A Survey of Nebulae Around Galactic Wolf-Rayet Stars in theSouthern Sky. III. Survey Completion and Conclusions"

Matthews, L.D., Gallagher m, J.S., van Driel, W. 1997, ASPConf. 117, ed. M. Persic, P. Salucci (ASP),p.98, "Exploration of the Tully-Fisher Relation in Low Surface Brightness Galaxies at the End of theSpiral Sequence"

McCarthy, P.J., Baum, S.A., Spinrad, H. 1996, ApJS, 106, p. 281, "Emission-Line Properties of 3CRRadio Galaxies. II. Velocity Fields in the Extended Emission Lines"

McMillan R.J., Ciardullo, R. 1996, ApJ, 473, p. 707, "Constraining theAges of Supernova Progenitors. I.Supernovae and Spiral Arms"

Mendez, R.A., et al. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 345, "A Large Proper-Motion Surveyin Plaut's Low-Extinction Window"

Mermilliod, J.-C, et al. 1997,A&A, 319, p. 481, "Red Giants in Open Clusters"

Minniti, D., et al. 1996, ApJ, 470, p. 953, "High-Dispersion Spectroscopy of Giants in Metal-PoorGlobular Clusters. II. Oxygen and Sodium Abundances"

Moitinho, A, et al. 1997, AJ, 113, p. 1359, "CCD UBV Photometry of the Young Open Cluster NGC3766"

Morel, T., St-Louis, N., Marchenko, S.V. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A.Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 271, "The 'Photosphere-WindConnection' in Wolf-Rayet Stars: Simultaneous Photometry and Spectroscopy of EZ Cma"

Morris, P.W., Eenens, P.R.J., Blum, R.D. 1996, ApJ, 470, p. 597, "Infrared Spectra of Massive Stars inTransition: WNL, Of, Of/WN, Be, B[e], and Luminous Blue Variable Stars"

Morris, P., et al. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E.Gosset, G. Rauw, (Universite de Liege), p. 405, "Evolutionary Implications for 'Transition' Stars fromGround-Based and ISO-SWS Spectra"

B-5

Niemela, V.S., et al. 1996, Rev. Mex. AA, 5, p. 100, "The Elliptic Orbit of the WR Binary System CVSerpentis"

Orosz, J.A., Bailyn, CD. 1997, ApJ, 477, p. 876, "Optical Observations of GRO J1655-40 inQuiescence. I. A Precise Mass for the Black Hole Primary"

Pahre, M.A., et al. 1997, ASP Conf. 114, ed. S.M. Viegas, R. Gruenwald, R.R. de Carvalho (ASP), p.137, "Discovery of a Galaxy Responsible for a DLA System at z = 3.15 and a Near-Infrared Search forPrimeval Galaxies"

Pak, S., Jaffe, D.T., Keller, L.D. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 28, "H2 Emission fromthe Inner 400 Parsecs of the Galaxy II. The UV-Excited H2"

Patten, B.M., Simon, T. 1996, ApJS, 106, p. 489, "The Evolution of Rotation and Activity in YoungOpen Clusters: IC 2391"

Patterson, J., et al. 1997, PASP, 109, p. 468, "Superhumps in Cataclysmic Binaries. XI. V603 AquilaeRevisited"

Perrett, K.M., et al. 1997, AJ, 113, p. 895, "The Globular Cluster Systems of NGC 1400 and NGC 1407"

Porto de Mello, G.F., Da Silva, L. 1997, ApJ, 482, L89, "HR 6060: The Closest Ever Solar Twin?"

Porto de Mello, G. F., Da Silva, L. 1996, Stellar Abundances Workshop, ed B. Barbury, W.J. Maciel,J.C, Gregorio-Hetem (IAG/USP), p. 59, "The Abundance Distribution of Solar-Type SolarNeighbourhood Stars"

Prinja, R.K., Fullerton, A.W., Crowther, P.A. 1996, A&A, 311, p. 264 "Variability in the Optical WindLines of HD 151804 (08 Iaf)"

Provencal, J.L., et al. 1997, ApJ, 480, p. 383, "Whole Earth Telescope Observations of the HeliumInteracting Binary PG 1346 + 082 (CR Bootis)"

Quillen, A.C, et al. 1997, ApJ, 481, p. 179, "Discovery of a Boxy Peanut-Shaped Bulge in the Near-Infrared"

Quillen, A.C, Ramirez, S.V., Frogel, J.A. 1996, ApJ, 470, p. 790, "Detection of Dynamical StructuresUsing Color Gradients in Galaxies"

Ramirez, A., Quintana, H., Way, M.J. 1997, ASP Conf. 114, ed. S.M.Viegas, R. Gruenwald, R.R. deCarvalho (ASP), p. 145, "Dark Halos around Elliptical Galaxies: NGC4782/3Group"

Ramirez; S.V., et al. 1997, AJ, 113, p. 1411, "Luminosity and Temperature from Near-Infrared SpectraofLate-Type Giant Stars"

Rauw, G., et al. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E.Gosset, G. Rauw, (Universite de Liege), p. 303, "A New Orbital Solution for the WNL Binary SystemWR12"

Reipurth, B., 1997, AJ, 114, p. 757, "Hubble Space Telescope Images of the HH 111 Jet"

B-6

Reipurth, B., Heathcote, S. 1997, IAU Symp. 182, ed. B. Reipurth, C Bertout (Kluwer), p.3, "50 Yearsof Herbig-Haro Research"

Riess, A.G., et al. 1997, AJ, 114, p. 722, "Time Dilation From Spectral Feature Age Measurements ofType la Supernovae"

Rodrigues, C.V., et al. 1997, ApJ, 485, p. 618, "Dust in the Small Magellanic Cloud: InterstellarPolarization and Extinction"

Rubin, R.H., et al. 1997, ApJ, 474, L131, "[Fe IV] In the Orion Nebula"

Rush, B., et al. 1997, ApJ,484, p. 163, "The High-Redshift Radio Galaxy MRC0406-244"

Sandquist, E.L., et al. 1996, ApJ, 470, p. 910, "CCD Photometry of the Globular Cluster M5. I. TheColor-Magnitude Diagram and Luminosity Functions"

Saraiva, M.F. 1997, AJ, 113, p. 1607, "BVRI and Ha Surface Photometry of the Triple-Ringed GalaxyIC4214"

Sarajedini, A., Geisler, D. 1996, AJ, 112, p. 2013, "Deep Photometry of the Outer Halo Globular Clusterin Pyxis"

Sarajedini, A., Layden, A. 1997, AJ, 113, p. 264, "Reddenings, Metallicities, and Possible AbundanceAnomalies in Young Globular Clusters"

Seitzer, P., Schweizer, F. 1997, ASP Conf. 116, ed. M. Arnaboldi, G.S. Da Costa, P. Saha (ASP), p. 504,"Young Globular Clusters in NGC 7252"

Sellgren, K., Blum, R.D., DePoy, D.L. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 285, "InterstellarExtinction and the Luminosity Function of Galactic Center Stars"

Stauffer, J.R., et al. 1997, ApJ, 475, p. 604, "Rotational Velocities and Chromospheric Activity of MDwarfs in the Hyades"

Stauffer, J.R., et al. 1997, ApJ, 479, p. 776, "Rotational Velocities and Chromospheric/Coronal Activityof Low-Mass Stars in the Young Open Clusters IC 2391 and IC 2602"

Storchi-Bergmann, T., et al. 1996, ApJ, 472, p. 83, "Circumnuclear Star Formation in Active Galaxies"

Storchi-Bergmann, T., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP),p. 302, "Infrared Emission-Line Signatures of Tori in the Nuclei of Seyferts"

Tiede, G. P., Terndrup, D.M. 1997, AJ, 113, p. 321, "A New Survey of Stellar Kinematics in the CentralMilky Way"

Tonry, J.L., et al. 1997, ApJ, 475, p. 399, "The SBF Survey of Galaxy Distances. I. Sample Selection,Photometric Calibration, and the Hubble Constant"

B-7

Wachter, S., Margon, B. 1996, AJ, 112, p. 2684, "Photometry of GX 349+2: Evidence for a 22-HourPeriod"

Wachter, S. 1997, ApJ, 485, p. 839, "Recovery of the X-Ray Transient QX Normae (=X1608-52) inOutburst and Quiescence"

Walker, A.R., Nemec, J.M. 1996, AJ, 112, p. 2026, "CCD Photometry of Galactic Globular Clusters, m.IC 4499"

Wallerstein, G., Gonzalez, G. 1996, MNRAS, 282, p. 1236, "The Carbon Cepheid V553 Cen: Evidenceof Triple-a and CNO Cycling"

Wampler, E.J., et al. 1996, A&A, 316, p. 33, "High Resolution Observations of the QSO BR 1202-0725:Deuterium and Ionic Abundances at Redshifts Above z = 4"

Wehrie, A.E., Keel, W.C, Jones, D.L. 1997, AJ, 114, p. 115, "The Nature of the Optical 'Jets' in theSpiral Galaxy NGC 1097"

Wilking, B.A., et al. 1997, PASP, 109, p. 549, "Herbig-Haro Objects in the p Ophiuchi Cloud"

Williams, R.M., et al. 1997, ApJ, 480, p. 618, "Supernova Remnants in the Magellanic Clouds. I. TheColliding Remnants DEM L316"

Wills, B.J., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 104, "TheHST Sample of Radio-Loud Quasars: Emission Lines from Lya to HP"

Wills, D., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 106, "TheHST Sample of Radio-Loud Quasars: Fe II and Other Correlations"

Wilson, A.S., Binette, L., Storchi-Bergman, T. 1997, ApJ, 482, L131, "The Temperature of ExtendedGas in Active Galaxies: Evidence for Matter-Bounded Clouds"

Winge, C, et al. 1996, ApJ, 469, p.648, "Spectroscopic Monitoring of Active Galactic Nuclei fromCTIO. II. IC 4329A, ESO 141-G55, Arakelian 120 and Fairall 9"

Zacharias, N. 1996, PASP, 108, p. 1135, "Measuring the Atmospheric Influence on DifferentialAstrometry: A Simple Method Applied to wide-Field CCD Frames"

Zhao, P., McClintock, J.E. 1997, ApJ, 483, p. 899, "A Dynamical Study of the Eclipsing Nova OY Arae"

Zucker, D., Wallerstein, G., Brown, J.A. 1996, PASP, 108, p. 911, "Abundances of Selected Elements inFive Oxygen-Poor Stars in Omega Centauri"

B-8

Publications by Telescope FY 1997Blanco 4-m = 64

1.5-m = 39

0.9-m = 25

1-m = 11

Curtis-Schmidt = 7

0.6-m = 2

Staff = 23

Total = 170

These figures include usage of more than one telescopeper publication.Total Publications FY 1997: 135

B-9

APPENDIX C

Kitt Peak National ObservatoryOctober 1996 through September 1997 Publications List

Abt, H.A. 1996, PASP, 108, p.844, "HD 105262, a Newly Discovered HR 4049 Star with a Large ProperMotion"

Abt, H.A. 1996, PASP, 108, p.1059, "HowLong AreAstronomical Papers Remembered?"

Abt, H.A., Tan, H., Zhou, H. 1997, ApJ, 487, p.365., "Hot Inner Disks That Appear and DisappearAround Rapidly Rotating A-Type Dwarfs"

Adelman, S.J., Philip, A.G.D., Adelman, C.J. 1996, MNRAS, 282, p.953, "Elemental Abundances of theMercury-Manganese Stars HR89 and 33 Geminorum"

Adelman, S.J., Philip, A.G.D. 1996, MNRAS, 282, p.1181, "Elemental Abundances of the B and A Stars- HI. Gamma Geminorum, HR 1397, HR 2154, HD 60825 and 7 Sextantis"

Ajhar, E.A., et al. 1997, AJ, 114, p.626, "Calibration of the Surface Brightness Fluctuation Method forUse with the Hubble Space Telescope"

Alves, J., et al. 1997, AJ, 113, p.1395, "Optical Outburst of a Pre-Main-Sequence Object"

Ambruster, C.W., et al. 1997, ApJ, 479, p.960, "The Extremely Active Single Giant IE 1751+7046 = ETDraconis: RevisedProperties and a Reevaluation of Its Evolutionary Status"

Andreon, S. 1996, A&A, 314, p.763, "The Morphological Segregation of Galaxies in Clusters. U. TheProperties of Galaxies in the Coma Cluster"

Appleton, P.N., Marston, AP. 1997, AJ, 113, p.201, "Multiwavelength Observations of Collisional RingGalaxies. I. Broad-Band Images, Global Properties, and Radial Colors of the SampleGalaxies"

Arnaboldi, M., et al. 1996, ApJ, 472, p.145, "The Kinematics of the Planetary Nebulae in the OuterRegions of NGC 4406"

Baliunas, S.L., et al. 1997, ApJ, 474, p.L119, "Properties of Sun-Like Stars with Planets: p1 Cancri, xBootis, and v Andromedae"

Bally, J., Devine, D., Alten, V. 1996, ApJ, 473, p.921, "A Parsec-Scale Herbig-Haro Jet in Barnard 5"

Bally, J., Devine, D., Reipurth, B. 1996, ApJ, 473, p.L49, "A Burst of Herbig-Haro Flows in NGC 1333"

Bally, J., et al. 1997, ApJ, 478, p.603, "New Herbig-Haro Flows in L1488 and L1455"

Bally, J. 1997, ASP Conf. 121, ed. D.T. Wickramasinghe (ASP), p.3, "Observations of Disks andOutflows from Young Stars"

Barnes, III, T.G., et al. 1997, PASP, 109, p.645, "BVRIJHK Photometry of Cepheid Variables"

C-l

Barsony, M., et al. 1997, APJS, 112, p.109, "A Near-Infared Imaging Survey of the p Ophiuchi CloudCore"

Baum, W.A., et al. 1997, AJ, 113, p.1483, "Distance to the Coma Cluster and a Value for H0 Inferredfrom Globular Clusters in IC 4051"

Bechtold, J., et al. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.122, "IR Spectroscopy of High-Redshift Quasars"

Becker, R.H., et al. 1997, ApJ, 479, p.L93, "The First Radio-Loud Broad Absorption Line QSO andEvidence for a Hidden Population of Quasars"

Belton, M.J.S., et al. 1996, Science, 274, p.377, "Galileo's First Images of Jupiter and the GalileanSatellites"

Bergeron, P., Ruiz, M.T., Leggett, S.K. 1997, ApJS, 108, p.339, "The Chemical Evolution of Cool WhiteDwarfs and the Age of the Local Galactic Disk"

Bianchi, L., et al. 1996, ApJ, 471, p.203, "Ultraviolet Extinction by Interstellar Dust in ExternalGalaxies: M31"

Bohannan, B. 1997, ASP Conf. 120, ed. A. Nota (ASP), p.3, "The Definition of Luminous BlueVariables"

Bohm, T., et al. 1996, A&AS, 120, p.431, "Azimuthal Structures in the Wind and Chromosphere of theHerbig Ae Star AB Aurigae. Results from the MUSICOS 1992Campaign"

Bond, H.E., et al. 1996, AJ, 112, p.2699, "Asteroseismological Observations of the Central Star of thePlanetary Nebula NGC 1501"

Bowen, D.V., et al. 1997, MNRAS, 284, p.599, "Redshifts of Galaxies Close to Bright QSO Lines ofSight"

Bower, G.A., et al. 1997, ApJ, 483, p.L33, "The Nuclear Ionized Gas in the Radio Galaxy M84 (NGC4374)"

Broeils, A.H., Courteau, S. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.74, "Modeling the MassDistribution in Spiral Galaxies"

Brown, J.A., et al. 1996, AJ, 112, p.1551, "Chemical Abundances in the Outer Disk Clusters Tombaugh2, Melotte 71, and NGC 2112"

Brunner, R.J., et al. 1997, ApJ, 482, p.L21, "Toward More Precise Photometric Redshifts: CalibrationVia CCD Photometry"

Burstein, D., et al. 1996, Gravitional Dynamics, ed. O. Lahav (Cambridge U. Press), p.141, "AReconsideration of the Peculiar Velocity Field within the Local Supercluster"

C-2

Caldwell, N., Rose, J.A. 1997, AJ, 113, p.492, "The Butcher-Oemler Effect at Low Redshift:Spectroscopy of Five Nearby Clusters of Galaxies"

Calzetti, D. 1997, AJ, 113, p.162, "Reddening and Star Formation in Starburst Galaxies"

Carpenter, J.M., et al. 1997, AJ, 114, p.198, "Properties of the Monoceros R2 StellarCluster"

Cavallo, R.M., Pilachowski, C.A., Rebelo, R. 1997, PASP, 109, p.226, "Oxygen Abundances in Metal-Poor Subgiant Stars from the O I Triplet"

Chaboyer, B., et al. 1996, MNRAS, 283, p.683, "An Accurate Relative Age Estimator for GlobularClusters"

Chambers, K.C., et al. 1996, ApJS, 106, p.247, "Ultra-Steep-Spectrum Radio Sources. II. Radio, Infrared,Optical, and HST Imaging of High-Redshift 4C Objects"

Chambers, K.C., et al. 1996, ApJS, 106, p.215, "Ultra-Steep-Spectrum Radio Sources. I. 4CObjects"

Chariot, S. 1996, The Universe at High-z, Large-Scale Structure and the Cosmic Microwave Background,ed. E. Martinez-Gonzalez (Springer), p.52, "Spectral Evolution of Galaxies"

Chen, H., et al. 1997, ApJ, 475, p.163, "IRAS 20050+2720: An Embedded Young Cluster Associatedwith a Multipolar Outflow"

Chromey, F.R., Hasselbacher, D.A. 1996, PASP, 108, p.944, "The Flat Sky: Calibration and BackgroundUniformity in Wide-Field Astronomical Images"

Chu, Y-H., Chang, T.H., Conway, G.M. 1997, ApJ, 482, p.891, "High-Resolution X-Ray Image of theHydrogen-Deficient Planetary Nebula Abell 30"

Cimatti, A., et al. 1997, The Early Universe with the VLT, ed. J. Bergeron (Springer), p.300, "KeckSpectropolarimetry of High z Radio Galaxies: Discerning the Components of the AlignmentEffect"

Clayton, G.C., et al. 1997, ApJ, 476, p.870, "Evidence for a BipolarGeometry in R Coronae Borealis?"

Connolly, A.J., et al. 1996, ApJ, 473, p.L67, "Superclustering at Redshift z = 0.54"

Connolly, A.J., et al. 1997, ApJ, 486, p.Lll, "The Evolution of the Global Star Formation History asMeasured from the Hubble Deep Field"

Corbin, M.R., Boroson, T.A. 1996, ApJS, 107, p.69, "Combined Ultraviolet and Optical Spectra of 48Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties"

Corbin, M.R., Boroson, T.A. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.260, "A New LuminosityEffect in QSO Spectra"

Cote, P., et al. 1997, ApJ, 476, p.L15, "Discovery of a Probable CH Star in the Globular Cluster M14 andImplications for the Evolution of Binaries in Clusters"

C-3

Coude du Foresto, V., Ridgway, S., Mariotti, J.-M. 1997, A&AS, 121, p.379, "Deriving ObjectVisibilities from Interferomgrams Obtained with a Fiber Stellar Interferometer"

Crotts, A.P.S., Tomaney, A.B. 1996, ApJ, 473, p.L87, "Results from a Survey of GravitationalMicrolensing Toward M31"

Crotts, A.P.S. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.289, "VATT/Columbia Microlensing SurveyofM31 and the Galaxy"

Crowther, P.A., Bohannan, B. 1997, A&A, 317, p.532, "The Distinction Between O Iafpe and WNLhaStars. A Spectral Analysis of HD 151804, HD 152408 and HDE 313846"

Crowther, P.A., Bohannan, B. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M.Vreux (Universite de Liege), p.437, "On the Nature of Olafpe Stars"

Da Costa, G.S., et al. 1996, AJ, 112, p.2576, "The Dwarf Spheroidal Companions to M31: WFPC2Observations of Andromeda I"

Dalcanton, J.J., et al. 1997, AJ, 114, p.635, "The Number Density of Low-Surface Brightness Galaxieswith 23< |io <25 V Mag/Arcsec"

Davis, D.S., et al. 1997, AJ, 114, p.613, "Gravitational Interactions in Poor Galaxy Groups"

De Young,D.S. 1996, AJ, 112,p.2896, "Numerical Simulations of Airflow in Telescope Enclosures"

De Young, D.S. 1996 IAU Symp.175, ed. R. Ekers (Kluwer), p.461, "Boundary Layers in ExtragalacticJets"

De Young, D.S. 1997, Phys. Fluids, 9, p.2168, "Growth of Large Scale Structures in Two-DimensionalMixing Layers"

De Young, D.S. 1997, 2nd Workshop on Gigahertz Peaked Spectrum and Compact Steep SpectrumRadio Sources, ed. I.A.G. Snellen (Sterrewacht Leiden), p.275, "How Do CSOs Grow Old?"

Devereux, N., Ford, H., Jacoby, G. 1997, ApJ, 481, p.L71, "Hubble Space Telescope Imaging of theCentral 1 Kiloparsec of M81"

Devereux, N.A., Duric, N., Scowen, P.A. 1997, AJ, 113, p.236, "Ha Far-Infrared and Thermal RadioContinuum Emission within the Late-Type Spiral Galaxy M33"

Devine, D., Reipurth, B., Bally, J. 1997, IAU Symp. 182 (Poster Papers), ed. F. Malbet (Observatoire deGrenoble), p.91, "New Herbig-Haro Objects"

Dey, A. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (WorldScientific), p.373, "The Host Galaxies of Distant Radio Sources"

Eikenberry, S.S., Fazio, G.G. 1997, ApJ, 475, p.L53, "Time Evolution and the Nature of the Near-Infrared Jets in GRS 1915+105"

C-4

Eikenberry, S.S., et al. 1997, ApJ, 477, p.465, "High Time Resolution Infrared Observations of the CrabNebula Pulsar and Pulsar Emission Mechanism"

Fekel, F.C, et al. 1997, AJ, 113, p.1095, "New and Improved Parameters of HD 202908 = ADS 14839:A Spectroscopic-Visual Triple System"

Fekel, F.C. 1997, PASP, 109, p.514, "Rotational Velocities of Late-Type Stars"

Feldmeier, J.J., Ciardullo, R., Jacoby, G.H. 1997, ApJ, 479, p.231, "Planetary Nebulae as StandardCandles. XI. Application to Spiral Galaxies"

Ferguson, A.M.N., et al. 1996, The Interplay Between Massive Star Formation, the ISM and GalaxyEvolution, ed. D. Kunth (Editions Frontieres), p.557, "Probing Star Formation in Low Gas DensityEnvironments: A Study of the Outer Disks of Galaxies"

Fesen, R.A., Gunderson, K.S. 1996, ApJ, 470, p.967, "Optical Spectroscopy and Imaging of theNortheast Jet in the Cassiopeia A Supernova Remnant"

Fesen, R.A., et al. 1997, AJ, 113, p.767, "Optical Imaging and Spectroscopy of the Galactic SupernovaRemnants CTB 1 (Gl 16.9+0.2), Gl 16.5+1.1, and Gl 14.3+0.3"

Fry, A.M., Carney, B.W. 1997, AJ, 113, p.1073, "Chemical Abundances of Galactic Cepheid VariablesThat Calibrate the P-L Relation"

Gallagher, J.S., Han, M., Wyse, R.F.G. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.66, "Structures ofDwarf Elliptical Galaxies in Rich Clusters"

Gang, T., et al. 1997, ASP Conf. 120,ed. A. Nota (ASP), p.l 10, "Atmospheric Conditions in LBVs: FirstResults from a High-Resolution Optical Survey"

Geisler, D., Claria, J.J., Minniti, D. 1997, PASP, 109, p.799, "Washington Photometry of Globular-Cluster Giants: Ten Intermediate-Metallicity Clusters"

Giacani, E.B., et al. 1997, AJ, 113, p.1379, "New Radio and Optical Study of the Supernova RemnantW44"

Gillett, F.C, et al. 1996,RevMexAA (Serie de Conferencias) 4, p.75, "The Gemini Telescopes Project"

Giovanelli, R., et al. 1997, AJ, 113, p.53, "The / Band Tully-Fisher Relation for Cluster Galaxies: ATemplate Relation, Its Scatter and Bias Corrections"

Giovanelli, R., et al. 1997, AJ, 113, p.22, "The / Band Tully-Fisher Relation for Cluster Galaxies: DataPresentation"

Gomez, M., Whitney, B.A., Kenyon, S.J. 1997, AJ, 114, p.l 138, "A Survey of Optical and Near-InfraredJets in Taurus Embedded Sources"

Gonzalez Delgado, R.M., et al. 1997, ApJ, 483, p.705, "Are the Super-Star Clusters of NGC 1569 in aPoststarburst Phase?"

C-5

Graham, J.R., Dey, A. 1996, ApJ, 471, p.720, "The Redshift of an Extremely Red Object and the Natureof the Very Red Galaxy Population"

Greenawalt, B., Walterbos, R.A.M., Braun, R. 1997, ApJ, 483, p.666, "Optical Spectroscopy of DiffuseIonized Gas in M31"

Grillmair, C.J., et al. 1996, AJ, 112, p.1975, "Hubble Space Telescope Observations of M32: The Color-Magnitude Diagram"

Grillmair, C.J., et al. 1997, AJ, 113, p.225, "The Nuclear Region of M51 Imaged with the HSTPlanetaryCamera"

Grillmair, C.J., et al. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.308, "Hubble Space TelescopeObservations of M32"

Guetter, H.H., Turner, D.G. 1997, AJ, 113, p.2116, "IC 1590, A Young Cluster Embedded in theNebulosity of NGC 281"

Guseva, N., Izotov, Y., Thuan, T.X. 1996, The Interplay Between Massive Star Formation, the ISM andGalaxy Evolution, ed. D. Kunth (Editions Frontieres), p.577, "The Internal Gas Motions in Blue CompactGalaxies"

Hall, P.B., Ellingson, E., Green, R.F. 1997, AJ, 113, p.l 179, "X-Ray Emission from the Host Clusters ofPowerful AGN"

Hall, P.B., et al. 1997, ApJ, 484, p.L17, "The Optical/Near-Infrared Colors of Broad Absorption LineQuasars, Including the Candidate Radio-Loud Broad Absorption Line Quasar 1556+3517"

Hamuy, M., et al. 1996, AJ, 112, p.2408, "BVRI Light Curves for 29 Type la Supernovae"

Hanson, M.M., Conti, P.S., Rieke, M.J. 1996, ApJS, 107, p.281, "A Spectral Atlas of Hot, LuminousStars at 2 Microns"

Hanson, M.M. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed.D. Kunth (Editions Frontieres), p.489, "AT-Band Spectroscopy in the Nearby Obscured HII Region M17:Newly Born Massive Stars"

Harris, W.M., et al. 1997, Science, 277, p.676, "Evidence for Interacting Gas Flows and an ExtendedVolatile Source Distribution in the Coma of Comet C/1996 B2 (Hyakutake)"

Heckman, T.M., et al. 1997, ApJ, 482, p.114, "A Powerful Nuclear Starburst in the Seyfert GalaxyMarkarian 477: Implications for the Starburst-Active Galactic Nucleus Connection"

Heiser, A.M. 1996, AJ, 112, p.2142, "Photometry of the RR Lyrae Variable U Comae"

Henden, A.A. 1996, AJ, 112, p.2757, "Faint Cepheid Studies. II. Stars with Published Periods"

Henry, R.B.C, et al. 1996, MNRAS, 283, p.635, "The Effects of Cluster Environment on the ChemicalEvolution of Galaxies - III. NGC 753"

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Hillenbrand, L.A. 1997, AJ, 113, p. 1733, "On the Stellar Population and Star-Forming History of theOrion Nebula Cluster"

Hintz, E.G., et al. 1997, PASP, 109, p.15, "Time-Series Ensemble Photometry of SX Phoenicis Stars. I.BL Camelopardalis"

Hintz, E.G., et al. 1997, AJ, 113, p.1375, "Reddening Study of a Bright High Galactic Latitude Nebula:LBN 434"

Hintz, E.G., Joner, M.D. 1997, PASP, 109, p.639, "Fourier Decomposition of the Light Curves of ThreeDwarf Cepheids: CY Aquarii, XX Cygni, and V798 Cygni"

Horner, D.J., Lada, E.A., Lada, C.J. 1997, AJ, 113, p. 1788, "A Near-Infrared Imaging Survey of NGC2282"

Hu, X. 1996, AJ, 112, p.2712, "Kinematic Studies of Herbig-Haro Objects in the OrionNebula"

Hubeney, I., Hubeney, V. 1997, ApJ, 484, p.L37, "Non-LTE Models and Theoretical Spectra ofAccretion Disks in Active Galactic Nuclei"

Hunter, D.A., Gallagher III, J.S. 1997, ApJ, 475, p.65, "An Emission-Line Study of Supergiant IonizedFilaments in Irregular Galaxies"

Hunter, D.A., et al. 1997, AJ, 113, p.1691, "Ultraviolet Photometry of Stars in the Compact Cluster R136in the Large Magellanic Cloud"

Hunter, D.A., et al. 1997, ApJ, 478, p.124, "The Intermediate-Mass Stellar Population of the LargeMagellanic Cloud Cluster NGC 1818 and the Universality of the Stellar Initial Mass Function"

Itoh, Y., Tamura, M., Kobayashi, Y. 1996, Proc. of the Third East-Asian Meeting on Astronomy:Ground-Based Astronomy in Asia, ed. N. Kaifu (National Astronomical Observatory, Japan), p.138,"Near Infrared Surveys of Taurus Molecular Cloud"

Izotov, Y.I., Thuan, T.X., Lipovetsky, V.A. 1997, ApJS, 108, p.l, "The Primordial Helium Abundance:Systemic Effects and a New Determination"

Izotov, Y.I., Thuan, T.X., Lipovetsky, V.A. 1996, The Interplay Between Massive Star Formation, theISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.587, "The Primordial HeliumAbundance"

Izotov, Y.I., et al. 1997, ApJ, 487, P.L37, "I Zw 18: A New Wolf-Rayet Galaxy"

Jannuzi, B.T., et al. 1996, ApJ, 470, p.Lll, "The Hubble Space Telescope Quasar Absorption Line KeyProject: The Unusual Absorption-Line System in the Spectrum of PG2302+029-Ejected or Intervening?"

Jannuzi, B.T. 1997, ASP Conf. 114, ed. S.M. Viegas (ASP), p.91, "The HST Quasar Absorption LineSurvey: A Census of Absorption Lines at Low Redshift"

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Jannuzi, B.T. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir(World Scientific), p.309, "The HST QuasarAbsorption Line Survey and the Relationship of Absorbersto Large Scale Structures"

Kaler, J.B., et al. 1996, PASP, 108, p.980, "Spectrophotometry of Planetary Nebulae. DX EDSObservations of Compact Nebulae"

Kaluzny, J. 1997, A&AS, 121, p.455, "CCDPhotometry of Distant OpenClusters. III. Berkeley 18"

Kaspi, S., et al. 1996, ApJ, 471, p.L75, "Measurement of the Broad-Line Region Size in Two BrightQuasars"

Kawara, K., et al. 1996, ApJ, 470, p.L85, "Infrared Spectroscopy of the Graviationally Lensed QuasarB1422+231: Mg II a2798 and Fe II Emission from the Broad-Line Gas at z = 3.62"

Keel, W.C. 1996, PASP, 108, p.917, "A Supergiant-Dominated Starburst in the Nucleus of NGC 4569"

Khare, P., et al. 1997, MNRAS, 285, p.167,"The Lyman Alpha Forest Towards B2 1225 + 317"

Kim, C, Joner, M.D. 1997, PASP, 109,p.951, "A Photometric Study of V798 Cygni"

Kormendy, J., et al. 1996, ApJ, 473, p.L91, "Hubble Space Telescope Spectroscopic Evidence for a1x 109 M0 Black Hole in NGC 4594"

Kormendy, J., et al. 1997, ApJ, 482, p.L139, "Spectroscopic Evidence for a Supermassive Black Hole inNGC 4486B"

Kraft, R.P., et al. 1997, AJ, 113, p.279, "Proton Capture Chains in Globular Cluster Stars. II. Oxygen,Sodium, Magnesium, and Aluminum Abundances in M13 Giants Brighter Than the Horizontal Branch"

Lacy, C.H.S., et al. 1997,AJ, 113, p.1088, "The SpectroscopicOrbit of II Ceti"

Lacy, C.H.S. 1997, AJ, 113, p.1406, "Absolute Dimensions and Masses of AD Bootis"

Lacy, C.H.S. 1997, AJ, 113, p.2226, "Absolute Dimensions and Masses of SW CanisMajoris"

Lacy, C.H.S., et al. 1997, AJ, 114, p.1206, "Absolute Dimensions andMasses of IT Cassiopeiae"

Laor, A., et al. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.l 16, "The HST Spectrum of I Zw 1:Implications of the C III ^1176 Emission Line"

Lauer, T.R., et al. 1996, ApJ, 471, p.L79, "Hubble Space Telescope Observations of the Double NucleusofNGC4486B"

Lauer, T.R., et al. 1997, ASP Conf. 116,ed. M. Arnaboldi (ASP), p.l 13, "The Central Structure of EarlyType Galaxies"

Layden, A.C, Sarajedini, A. 1997, ApJ, 486, p.L107, "The Globular Cluster M54 and the Star FormationHistory of the Sagittarius Dwarf Galaxy"

Lehnert, M.D., Heckman, T.M. 1996,ApJ, 472, p.546, "The Nature of Starburst Galaxies"

Lopez-Cruz, O., et al. 1997, ApJ, 475, p.L97, "Are Luminous cD Halos Formed by the Disruption ofDwarf Galaxies?"

Malhotra, S., Rhoads, J.E., Turner, E.L. 1997, MNRAS, 288, p.138, "Through a Lens Darkly: Evidencefor Dusty Gravitational Lenses"

Martin, C.L. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed.D. Kunth (Editions Frontieres), p.579, "The Dynamic Interstellar Medium in Dwarf Galaxies: A CaseStudy oflZW 18"

Mason, B.D. 1996, AJ, 112, p.2260, "ICCD Speckle Observations of Binary Stars. XV. An Investigtationof Lunar Occultation Systems"

Mason, B.D. 1997, AJ, 114, p.808, "Binary Star Orbits from Speckle Interferometry. XI. Orbits ofTwelve Lunar Occultation Systems"

Mason, C.G., et al. 1996, ApJ, 470, p.577, "Infrared Observations of Dust Formation and CoronalEmission in Nova Aquilae 1995"

Massey, P., et al. 1996, ApJ, 469, p.629, "The UV-Brightest Stars of M33 and Its Nucleus: Discovery,Photometry, and Optical Spectroscopy"

Massey, P. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite deLiege), p.361, "Numbers and Distribution of Wolf-Rayet Stars in Local Group Galaxies; Clues toMassive Star Evolution"

Mathys,G., et al. 1997, A&AS, 123, p.353, "The Mean MagneticField Modulus of Ap Stars"

McCall, M.L., Buta, R.J. 1997, AJ, 113,p.981, "Discovery of a Second Companion of Dwingeloo 1"

McCarthy, P.J., Baum, S.A., Spinrad, H. 1996, ApJS, 106, p.281, "Emission-Line Properties of 3CRRadio Galaxies. II. Velocity Fields in the Extended Emission Lines"

McMillan, R.J., Ciardullo, R. 1996, ApJ, 473, p.707, "Constraining the Ages of SupernovaProgenitors. I.Supernovae and Spiral Arms"

McNamara, D.H., Powell, J.M., Joner, M.D. 1996, PASP, 108, p.1098, "The Physical Properties of theSX Phoenicis Star CY Aquarii"

Meech, K.J., et al. 1997, AJ, 113, p.844, "Observations of Structures in the Inner Coma of Chiron withthe HST Planetary Camera"

Meyer, M.R., et al. 1996, Disks and Outflows Around Young Stars, ed. S. Beckwith (Springer), p.175,"The Stellar Populations of Deeply Embedded Young Clusters: Near-Infrared Spectral Classification"

Mikolajewska, J., Kenyon, S.J. 1996, AJ, 112, p.1659, "The Inscrutable Hot Component in the SymbioticBinary Z Andromedae"

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Moody, J.W., et al. 1997, AJ, 113, p.1022, "Discovery of a Faint Carbon Star at High Galactic Latitude"

Moran, E.C, Halpern, J.P., Helfand, D.J. 1996, ApJS, 106, p.341, "Classification of /#AS-Selected X-Ray Galaxies in the ROSATAll-Sky Survey"

Morris, P.W., et al. 1996, ApJ, 470, p.597, "Infrared Spectra of Massive Stars in Transition: WNL, Of,Of/WN, Be B[e], and Luminous Blue Variable Stars"

Morris, P. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite deLiege), p.405, "Evolutionary Implications for "Transition" Stars from Ground-Based and ISO-SWSSpectra"

Morrison, H.L., et al. 1997, AJ, 113, p.2061, "Stellar Populations in Edge-On Galaxies from Deep CCDSurface Photometry. II. One-Dimensional Fits of NGC 891"

Mueller, B.E.A., Ferrin, I. 1996, Icarus, 123, p.463, "Change in the Rotational Period of Comet P/Tempel2 between the 1988 and 1994 Apparitions"

Mukherjee, J., Peters, G.J., Wilson, R.E. 1996,MNRAS, 283, p.613, "Rotation of Algol Binaries - a LineProfile Model Applied to Observations"

Mulchaey, J.S., Regan, M.W., Kundu, A. 1997, ApJS, 110, p.299, "The Fueling of Nuclear Activity. I. ANear-Infrared Imaging Survey of Seyfert and Normal Galaxies"

Mulchaey, J.S., Regan, M.W. 1997, ApJ, 481, p.L135, "The Fueling of Nuclear Activity: The BarProperties of Seyfert and Normal Galaxies"

Munn, J.A., et al. 1997, ApJS, 109, p.45, "The Kitt Peak Galaxy Redshift Survey with MulticolorPhotometry: Basic Data"

Noble, J.C, et al. 1997, AJ, 113, p.1995, "The Time Scales of the Optical Variability of Blazars. IV. 01090.4"

Noriega-Crespo, A., et al. 1997, ApJ, 486, p.L55, "The Proper Motions of the Warm MolecularHydrogen Gas in Herbig-Haro 1"

O'Neal, D., Neff, J.E. 1997, AJ, 113, p.l 129, "OH 1.563 urn Absorption from Starspots on Active Stars"

Orosz, J.A., Wade, R.A., Harlow, J.J.B. 1997, AJ, 114, p.317, "Variable Radial Velocities AmongComposite-Spectrum Binaries in the PG Catalog"

Osmer, P.S., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir(World Scientific), p.405, "Spectroscopic Observations of Quasar Candidates from a Deep MulticolorSurvey"

Papaderos, P., et al. 1996, A&AS, 120, p.207, "Optical Structure and Star Formation in Blue CompactDwarf Galaxies. I. Observations and Profile Decomposition"

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Parker, J.W., et al. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution,ed. D. Kunth (Editions Frontieres), p. 537, "Starburst Anatomy: Resolved and Composite Properties ofGiant HII Regions in the Pinwheel Galaxy (Messier 33)"

Patterson, R.J., Thuan, T.X. 1996, ApJS, 107, p.103, "Surface Photometry of Low Surface BrightnessDwarf Irregular Galaxies"

Perrett, K.M., et al. 1997, AJ, 113, p.895, "The Globular ClusterSystems of NGC 1400 and NGC 1407"

Pesce, J.E., et al. 1997,ApJ, 486, p.770, "Multiwavelength Monitoring of the BL Lacertae Object PKS2155-304 in 1994 May. I. The Ground-Based Campaign"

Phelps, R.L., Lada, E.A. 1997, ApJ, 477, p.176, "Spatial Distribution of Embedded Clusters in theRosette Molecular Cloud: Implications for Cluster Formation"

Phelps, R.L. 1997, AJ, 114, p.826, "Berkeley 17: The OldestOpenCluster?"

Pilachowski, C, et al. 1997, AJ, 114, p.819, "Carbon Isotope Ratios from the First Overtone CO Bandsin Metal-Poor Giants"

Pilachowski, C.A. 1996,CCD Astronomy, 3, no.3, p.50, "Save Those Bits"

Polyansky, O.L., et al. 1997, Science, 277, p.346, "Water on the Sun: Line Assignments Based onVariational Calculations"

Prestwich, A.H., et al. 1997, ApJ, 477, p.144, "A Search for the Cooling Flow Accretion Population:Optical and Near-Infrared Imaging of NGC 1275"

Provencal, J.L., et al. 1997, ApJ, 480, p.383, "Whole Earth Telescope Observations of the HeliumInteracting Binary PG 1346+082 (CR Bootis)"

Pustilnik, S., et al. 1996, The Interplay Between MassiveStar Formation, the ISM and Galaxy Evolution,ed. D. Kunth (Editions Frontieres), p.585, "The Chemical Evolutionof Blue Compact Galaxies: OxygenAbundance vs Gas Content"

Puxley, P., Boroson, T. 1997, SPIE, 2871, p.744, "Observing with a 21st Centry Ground-BasedTelescope - or How to Do Unique Science with the Gemini Telescopes"

Rachford, B.L. 1997, ApJ, 486, p.994, "Chromospheric Activity in Dwarf and Evolved Late A- and EarlyF-Type Stars"

Ram, R.S., Bernath, P.F., Wallace, L. 1996, ApJS, 107, p.443, "Near-Infrared Spectroscopy of TiO:Laboratory Measurements and Identification in Sunspots"

Rand, R.J. 1997, ApJ, 474, p.129, "A Very Deep Spectrum of the Diffuse Ionized Gas in NGC 891"

Regan, M.W., Elmegreen, D.M 1997, AJ, 114, p.965, "AT-Band Observations of Barred Spiral Galaxies"

Reynoso, E.M., et al. 1997, A&A, 317, p.203, "Neutral Hydrogen Compact Absorption Features inCassiopeia A"

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Rhoads, J.E. 1997, ApJ, 487, p.Ll, "How To Tell a Jet from a Balloon: A Proposed Test for Beaming inGamma-Ray Bursts"

Rubin, V.C, Kenney, J.D.P., Young, J.S. 1997, AJ, 113, p.1250, "Rapidly Rotating Circumnuclear GasDisks in Virgo Disk Galaxies"

Ryden, B.S., et al. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.283, "Dwarf Elliptical and DwarfSO Galaxies in the Virgo Cluster"

Sakai, S., et al. 1997, ApJ, 478, p.49, "Detection of the Tip of the Red Giant Branch in NGC 3379(Ml05) in the Leo I Group Using the Hubble Space Telescope"

Samec, R.G., et al. 1997, AJ, 113, p.800, "UBVRI CCD Observations and Analyses for the Near-ContactBinary, LP Cephei"

Sarajedini, A., Geisler, D. 1996, AJ, 112, p.2013, "Deep Photometry of the Outer Halo Globular Clusterin Pyxis"

Sarajedini, A. 1997, AJ, 113, p.682, "Palomar 14: A Young Globular Cluster in the Outer Galactic Halo"

Sarajedini, A., Layden, A. 1997, AJ, 113, p.264, "Reddenings, Metallicities, and Possible AbundanceAnomalies in Young Globular Clusters"

Sarajedini, V., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir(World Scientific), p.411, "Faint AGN/Starburst Nuclei in MDS Galaxies"

Sarajedini, V.L., et al. 1996, ApJ, 471, p.L15, "Compact Nuclei in Moderately Redshifted Galaxies"

Schade, D., Barrientos, L.F., Lopez-Cruz, O. 1997, ApJ, 477, p.L17, "Evolution of Cluster Ellipticals at0.2 < z < 1.2 from Hubble Space Telescope Imaging"

Schechter, P.L., et al. 1997, ApJ, 475, p.L85, "The Quadruple Gravitational Lens PG 1115+080: TimeDelays and Models"

Scodeggio, M., Giovanelli, R., Haynes, M.P. 1997, AJ, 113, p.101, "The Relative Distance Between theClusters of Galaxies A2634 and Coma"

Seeker, J., Harris, W.E. 1996, ApJ, 469, p.623, "The Early-Type Dwarf-to-Giant Ratio and Substructurein the Coma Cluster"

Seeker, J. 1996, ApJ, 469, p.L81, "A Constraint on the Formation of Dwarf Elliptical Galaxies in theDense Coma Cluster Core"

Silva, D.R., Bothun, G.D. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.208, "Elliptical Galaxies:Young or Old?"

Smalley, B., et al. 1997, MNRAS, 284, p.457, "The Chemical Composition and Binarity of P Crateris"

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Sogawa, H., et al. 1997, AJ, 113, p. 1057, "Infrared Polarimetry of Star-Forming Regions: The SerpensCloud Core"

Solanki, S.K., et al. 1996, A&A, 315,p.303, "The Beatof the SolarChromsophere's Cold Heart"

Spinrad, H., et al. 1997, ApJ, 484, p.581, "LBDS 53W091: An Old, Red Galaxy at z = 1.552"

Stauffer, J.R., et al. 1997, ApJ, 475, p.604, "Rotational Velocities and Chromospheric Activity of MDwarfs in the Hyades"

Steidel, C.C., et al. 1997, ApJ, 480, p.568, "Quasar Absorbing Galaxies at z< 1: Deep Imaging andSpectroscopy in the Field of 3C 336"

Stern, D., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir(World Scientific), p.413, "Radio Galaxies from the 5 GHZ MG Catalog"

Stetson, P.B. 1997, Baltic Astronomy, 6, p.3, "Some InterestingColor-MagnitudeDiagrams"

Strassmeier, K.G. 1996, A&A, 314, p.558, "Doppler Imaging of Stellar Surface Structure. I. The Rapidly-Rotating RS CVn Binary UZ Librae"

Strassmeier, K.G. 1997, A&A, 319, p.535, "Doppler Imaging of Stellar Surface Structure, m. The X-RaySource HD 116544 = IN Virginis"

Strassmeier, K.G., Hubl, B., Rice, J.B. 1997, A&A, 322, p.511, "Doppler Imaging of Stellar SurfaceStructure. IV. The Rapidly-Rotating G5III-IV Star HD 112313 = IN Comae"

Sugitani, K., Tamura, M, Ogura, K. 1996, Proc. of the Third East-Asian Meeting in Astronomy: Ground-Based Astronomy in Asia, ed. N. Kaifu (National Astronomical Observatory, Japan), p.183, "Small-ScaleSequential Star Formation in Bright-Rimmed Clouds"

Tamura, M., et al. 1996, AJ, 112, p.2076, "Interferometric Observations of Outflows from Low-MassProtostars in Taurus"

Taniguchi, Y., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir(World Scientific), p.415, "MGII & Fell Emission of a High-z Quasar B1422+231"

Thaller, M., Gies, D. 1997, RevMexAA, Serie de Conferencias 5, p.l 17, "Ha Detection of CollidingWinds in O-Type Binaries"

Titus, T.N., Spillar, E.J., Johnson, P. 1997, AJ, 114, p.958, "Population Analysis of Faint Galaxies withMixture Modeling"

Tolstoy, E. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D.Kunth (Editions Frontieres), p.67, "The Colour-Magnitude Diagrams of Three Nearby Dwarf IrregularGalaxies"

Tomaney, A.B., Crotts, A.P.S. 1996 AJ, 112, p.2872, "Expanding the Realm of Microlensing Surveyswith Difference Image Photometry"

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Tonry, J.L., et al. 1997, ApJ, 475, p.399, "The SBF Survey of Galaxy Distances. I. Sample Selection,Photometric Calibration, and the Hubble Constant"

Tran, H.D., et al. 1997, PASP, 109, p.489, "Probing the Geometry and Circumstellar Environment of SN1993JinM81"

Tripp, T.m., Lu, L., Savage, B.D. 1997, APJS, 112, p.l, "High Signal-to-Noise Echelle Spectroscopy ofQuasar Absorption Line Systems with Metals in the Direction of HS 1700+6416"

Tsay, W.S., Chen, A., Chen, R. 1997, Baltic Astronomy, 6, p.141, "Snapshots of CCD Fields in a Studyof the Verticle Distribution of Stars"

Turner, D.G., Mandushev, G.I., Welch, G.A. 1997, AJ, 113, p.2104, "Galactic Clusters with AssociatedCepheid Variables. V. The Case of SU Cygni"

Tweedy, R.W., Kwitter, K.B. 1996, ApJS, 107, p.255, "An Atlas of Ancient Planetary Nebulae and TheirInteraction with the Interstellar Medium"

Ulmer, MP., et al. 1996, AJ, 112, p.2517, "Low Surface Brightness Galaxies in the Core of the ComaCluster"

Van Zee, L., et al. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution,ed. D. Kunth (Editions Frontieres), p.563, "HI and Optical Studies of UGCA 20"

Vreux, J.-M., et al. 1996, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux(Universite de Liege), p.337, "Line-Profile Variability and Mass-Transfer in the Early Type BinaryBD+40°4220"

Wakker, B., et al. 1996, ApJ, 473, p.834, "The Distance to Two Neutral Hydrogen Clouds: The High-Velocity Complex A and the Low-Latitude Intermediate-Velocity Cloud"

Wallace, L., Hinkle, K. 1996, ApJS, 107, p.312, "High-Resolution Spectra of Ordinary Cool Stars in theK-Band"

Wallace, L., Hinkle, K. 1997, APJS, 111, p.445, "Medium-Resolution Spectra of Normal Stars in the£-Band"

Walter, F., et al. 1997, AJ, 113, p.2031, "A Dynamical Analysis of the H B Galaxy B Zwicky 33 and ItsLow Surface Brightness Companion"

Walterbos, R.A.M., Braun, R. 1996, ASP Conf. 106, ed. E.D. Skillman (ASP), p.l, "The Cool and WarmPhases of the Interstellar Medium in Spiral Galaxies"

Wang, J., et al. 1997, ApJ, 474, p.659, "An X-Ray and Optical Investigation of the Infrared-LuminousGalaxy Merger Markarian 266"

Wang, Q.D., Connolly, A.J., Brunner, R.J. 1997, ApJ, 487, p.L13, "A2125 and Its Environs: Evidence foran X-Ray-Emitting Hierarchical Superstructure"

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Watson, J.K., Meyer, D.M. 1996, ApJ, 473, p.L127, "Observations of Ubiquitous Small-Scale Structurein the Diffuse Interstellar Medium"

Weis, E.W. 1996, AJ, 112, p.2300, "Photometry ofStars with Large Proper Motion"

Welty, D.E., Morton, D.C, Hobbs, L.M. 1996, ApJS, 106, p.533, "A High-Resolution Survey ofInterstellar Ca II Absorption"

Whitney, B.A., Kenyon, S.J., Gomez, M. 1997, ApJ, 485, p.703, "Near-Infrared Imaging Polarimetry ofEmbeddedYoung Stars in the Taurus-Auriga MolecularCloud"

Willick, J.A., et al. 1997, ApJS, 109, p.333, "Homogeneous Velocity-Distance Data for Peculiar VelocityAnalysis, ffl. The Mark III Catalog of GalaxyPeculiar Velocities"

Wise, M.W., Silva, D.R. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.364, "Dust Populations inElliptical Galaxy Cores"

Wolff, S.C, Simon, T. 1997, PASP, 109, p.759, "The Angular Momentum of Main-Sequence Stars andits Relation to Stellar Activity"

Worek, T.F. 1996, PASP, 108, p.962, "The Rossiter-McLaughlin Rotation Effect Observed for AlDraconis and V505 Sagittarii"

Wu, K.L., Faber, S.M., Lauer, T.R. 1997, The Hubble Space Telescope and the High Redshift Universe,ed. N.R. Tanvir (World Scientific), p.179, "Tests of Morphological Peculiarity Indices for Distant andLocal Galaxies"

Yanny, B., Jannuzi, B.T., Impey, C 1997, ApJ, 484, p.L113, "Hubble Space Telescope Imaging of theBL Lacertae Object OJ 287"

Young, J.S., et al. 1996, AJ, 112, p.1903, "The Global Rate and Efficiency of Star Formation in SpiralGalaxies as a Function of Morphology and Environment"

Yu, K.C., Bally, J., Devine, D. 1997,ApJ, 485, p.L45, "Shock-Excited H2 Flows in OMC-2 and OMC-3"

Zacharias, N. 1996, PASP, 108, p.1135, "Measuring the Atmospheric Influence on DifferentialAstrometry: A Simple Method Applied to Wide-Field CCD Frames"

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APPENDIX D

National Solar ObservatoryOctober 1996 through September 1997 Publications List

Abrams, D., Kumar, P. 1996, ApJ,472, p. 882, "Asymmetries of Solarp-Mode Line Profiles"

Alexander, D., et al., 1996, SolarWind Eight Workshop, eds. D. Winterhalter, J.T. Gosling, S.R. Habbal,et al. (AIP), p. 80, "The Large Scale EruptiveEvent of April 14 1994"

Altrock, R.C. 1997, Sol. Phys., 170, p. 411, "An 'Extended Solar Cycle' as Observed in Fe XIV"

Altrock, R.C, Henry, T.W. 1997, Solar-Geophysical Data, Part 1 (Prompt Reports), no. 619-630, ed.H.E. Coffey, "Sacramento Peak Coronal Line Synoptic Maps, 1996"

Altrock, R.C, Henry, T.W. 1997, Solar-Geophysical Data, Part 1 (Prompt Reports), no. 619-630, ed.H.E. Coffey, "Coronal Line Emission (Sacramento Peak), 1996"

Altrock, R.C, et al. 1997, Contributions of the Astronomical Observatory Skalnate Pleso, 27, p. 25,"Coronal Index of Solar Activity for 1996"

Aschwanden, M.J., Benz, A.O. 1997, ApJ, 480, p. 825, "Electron Densities in Solar Flare Loops,Chromospheric Evaporation Upflows, and Acceleration Sites"

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