1

Calendar of Events March Meeting

Friday, MAR. 10, 2006 1001 Malott

7:30 PM NOVA SPECIAL

E=mc2—Einstein’s Famous Equation-2

SPACE NIGHT

Sunflower Elementary Tuesday,

March 28, 7 - 9 PM.

PUBLIC OBSERVING Sunday APR. 02, 2006

8:30PM Memorial Stadium

President: Hannah Swift hkswift@ku.edu Treasurer: Dr. Steve Shawl Shawl@ku.edu University Advisor: Dr. Bruce Twarog btwarog@ku.edu Webmaster: Gary Webber gwebber@ku.edu Events Coordinator Rick Heschmeyer rcjbm@sbcglobal.net

Report From the Officers on the February Meeting:

Just another reminder in case you still haven’t gotten to it: please return your Annual Dues using the form and envelope in the January newsletter. The dues primarily go to cover the cost of our inclusion in the Astronomical League, the organization that serves as a national voice/conduit for hundreds of amateur as-tronomy clubs throughout the US. The Reflector, pub-lished quarterly, is one of the benefits of membership

in the AL, not to mention the fact that the national headquarters is based in Kansas City. We returned to our regular schedule of meetings in February, showing the first of the excellent two-part series on Albert Einstein and the development of thought that went into the equation E=mc2 . There will be another regular monthly meeting in March, Friday the 10th at 7:30 PM in 1001 Malott. (NOTE that the date is a little earlier than normal for the month. The 17th would have been the usual date, but this is the Friday of Spring Break at KU, so we moved the meeting up one week.) We will show the second part of the two-part special from NOVA: Einstein’s Famous Equation—E =mc2 . If you missed the first part—don’t worry. The historical background is excellent, but Part II stands on its own and focuses more on Einstein and how he arrived at the notion that mass and energy were equivalent. The series is well done, so if you missed it when it appeared on PBS the first time, join us for a look and some discussion. As a coincidental bonus, Tuesday March 14 is the anni-versary of Einstein’s birth in 1879. There is a special event planned for March 28th, organized by Rick Heschmeyer; please read through the announcement below and lend a hand if you have the time. To those of you who attended the talk by Alan Stern, you may want to take a look at the article in this issue on the HST results for the moons of Pluto and the possi-bility of rings around the planet. Even more exciting from an observational stand-point is the discovery by the SWIFT satellite of a gamma-ray burst and the associ-

Volume 32 Number 03 MARCH 2006

F r o m t h e O f f i c e r s

INSIDE THIS ISSUE

From the Officers (continued) 2

The Neptune File—Review 3

Astronomers Agog 4

March 10 Meeting POSTER 5

Pluto Might Have Rings 6

Cosmic-Ray Source 7

Astronomers (continued) 8

Micro-Sats 9

SPECIAL EVENT: REQUEST FOR HELP SPACE NIGHT

Sunflower Elementary School - Tuesday, March 28, 7 - 9 PM. Rick Heschmeyer has organized the event and is expecting be-tween 60 and 100 people. It is for all three third grade classes

and their families. In addition to telescope viewing, there will be stations set up inside where the kids can drive a "Planetary rover" as well as make a crater. Rick would like to get 2 club members

to bring their telescopes for the evening for the telescope observ-ing part. The teachers and a couple of parents are going to assist with the indoor activities. If you are interested in helping Rick with

one of the primary missions of the club, please contact him at rcjbm@sbcglobal.net.

2

ated supernova, a star within optical reach of an 8-inch telescope equipped with a CCD. A phenomenal role exists for amateur astronomy along the lines of the coordinated variable star campaigns organized by the AAVSO. Our next public observing session at Memorial Stadium is Sunday April 02 at 8:30 PM. (Daylight Savings Time starts this particular Sunday. Again, we moved back one Sunday to avoid issues with the end of Spring break on the 26th of March.) I f you wish to help and/or set up a telescope, let us know—you are always welcome. The observing in Febru-ary was excellent. Clear and dark skies (new moon), relatively stable atmosphere and, unlike January, reasonably warm. Thanks to Rick Heschmeyer and Jon Voisey for coming out to help with the telescopes. We have received brochures and info on the Heart of America Star Party, sponsored by the Astronomical Society of Kansas City. The HASP takes place from June 22 through the 25 at a site 75 miles south of Kansas City. If you have questions, contact Dan Johnson (gdj102356@hotmail.com) or Paul Thompson (pjtom@highstream.net) . As a local event, it is a bit easier to get to than the Annual Nebraska Star Party, which takes place near Valentine, NE. The scheduled dates for NSP this year are July 23 through 28, 2006. We will bring the materials on both events to the next meeting. If you’d like additional details, the web site for the NSP is www.NebraskaStarParty.org or email at info@NebraskaStarParty.org or via a hotline to Doug Bell, one of the organizers of the event, by calling 402-489-8197. If you’ve never been there, the site is rather lovely and, when the weather is clear, the skies are impressively dark. The Astronomical League has many activities to encourage amateur astronomy including Observing Clubs. The Ob-serving Clubs offer certificates of accomplishment for demonstrating observing skills with a variety of instruments and objects. Each Club offers a certificate based upon achieving certain observing goals. These are usually in the form of a specific number of objects of a specific group with a given type of instrument. Occasionally there are multiple levels of accomplishment within the club. There is no time limit for completing the required observing, but good record keeping is required. When you have reached the requisite number of objects, your observing logs are examined by the appropriate

authority and you will receive a certificate and pin to proclaim to all that you have reached your goal. Many local astronomical societies even post lists of those who have obtained their certificates. This month we feature the details on the Sunspotters Club. The purpose of this program is to encourage solar observing with an eye toward educating the amateur astronomer on solar features and their evo-lution. By following this regimen the observer will learn the various features of solar activity, learn how these change during their passage across the disk, and learn how to develop a regular observing pro-gram. Before you start any solar observing program, make absolutely certain that you have safe filters and a safe set-up. Only use filters from reputable sources, and never use a "solar filter" that screws

into an eyepiece. As Richard Hill states in Observe and Understand the Sun: "Observing the sun is the only inherently dangerous observing an amateur astronomer can do. Be aware of this at all times and take all necessary precautions. If you do not know a filter or procedure is safe then do not use it! Always err on the side of safety. An eye once damaged is forever damaged. Filters that let too much INFRARED light through can burn an eye if used visually. There is NO PAIN when this happens. Burned retinas can not be repaired. Excessive ULTRAVIOLET light has been shown to cause cataracts. So be very careful." In the League's Sunspotter program, you will make two sets of drawings. The first set is five detailed sketches of sunspot groups. The second set is 20 or more sketches of the whole solar disk during two so-lar rotations (one rotation is about 30 days). Artistic skill is not a requirement! Just diagram what you see as well as your skills allow. Use a number 2A lead pencil for best results. For more details, go to http://www.astroleague.org/al/obsclubs/sunspot/sunsptcl.html

If you have any suggestions for talks, speakers, or public events, please feel free to contact us, particularly Rick Heschmeyer (rcjbm@sbcglobal.net), the events coordinator for the club. Hope to see you later this

month at the regular monthly meeting in MARCH. ALL for now.

(Continued from page 1)

About the Astronomy Associates of Lawrence The club is open to all people interested in sharing their love for astronomy. Monthly meetings are typically on the second Friday of each month and often feature guest speakers, presentations by club members, and a chance to exchange ama-teur astronomy tips. Approximately the last Sunday of each month we have an open house on Memorial Stadium. Periodic star parties are scheduled as well. For more information, please contact the club officers:Hannah Swift at hkswift@ku.edu, Gary Webber at gwebber@ku.edu, our faculty advisor, Prof. Bruce Twarog at btwarog@ku.edu. or our events coordinator, Rick Heschmeyer at rcjbm@sbcglobal.net. Because of the flexibility of the schedule due to holidays and alternate events, it is always best to check the Web site for the exact Fridays and Sundays when events are scheduled. The information about

AAL can be found at http://www.ku.edu/~aal.

Copies of the Celestial Mechanic can also be found on the web at http://www.ku.edu/~aal/celestialmechanic

F r o m t h e O f f i c e r s , c o n t i n u e d

3

Review of the book The Neptune File

By Tom Standage

The title comes from a scrapbook of original documents relating to the discovery of Neptune in September,

1846. It was owned by then Astronomer Royal, George Airy. But the author’s Neptune File discusses the discovery

of all planets beyond Saturn, from the chance discovery of Uranus in March 1781 through the tens of planets beyond the Solar System dis-covered by 2001. The book is a pleasant read, reminiscent of the “Astronomical Scrap-book” columns by the late Joseph Ashbrook in Sky and Telescope. It is a good follow-on to the recent AAL meeting about modern methods of planet searching, and as back-ground to frequent news of new planet discovery. Yet the 240-page book is scholarly with extensive notes and bibliography and the charm of 1895 sketches of famous astronomers and instruments. Besides giving good detail about how each new planet was discovered, this book is loaded with intriguing little known facts. A few: The name Neptune was seriously pro-posed for Uranus, and astronomers’ names for Uranus, Neptune, and Pluto. Percival Lowell left funds to continue the search for future Pluto, but his wife legally fought the be-quest for years. But once the planet was discovered she wanted in named Lowell, or even her first name! Lowell made several different mathematical predictions of where to search for Pluto, and it was discovered photographically in 1930 by future KU student Tombaugh, six degrees from one of the predicted positions. Yet this was coincidental. Pluto is too small to significantly affect the orbit of Neptune. W. Herschel found Uranus with a 7-inch F12 Newtonian, speculum mirror, wooden tube for both scope and oculars. His son John played a role in the naming of Neptune. English graduate student Adams gave Airy his Neptune predictions 8 months before French astronomer Le Verrier gave his equally accurate ones to Airy. Airy had English astronomer Challis start searching in July 1846 using Le Verrier’s calculations, but Challis was sloppy. In September Le Verrier gave his predictions to German astronomer Galle, who confirmed Neptune on his second night. The circumstances led to decades of international bitterness but promise of finding more planets indirectly. Neptune File sweeps the reader from classical planetary astronomy to its slow rebirth and then revolution in the space age. Read it!

PRIME FOCUS William Winkler

Besides working with Frail on radio observations, Soderberg will scrutinize the supernova in the coming months with both the Hubble Space Telescope and the Chandra X-ray Observatory. These observa-tions will help nail down the explosion's total energy and the properties of the host galaxy — vital clues to unraveling the GRB's fundamental nature. Astronomers predict that the supernova will brighten to perhaps 16th magnitude around March 5th. This brightness is easily within the grasp of high-quality amateur telescopes equipped with CCD cameras. The American Association of Variable Star Observers (AAVSO) is organizing a worldwide observing campaign to monitor the supernova's light output as it brightens to a peak and then fades from view. "The emerging supernova is well positioned in the early evening sky for professional and amateur monitoring," says Aaron Price of the AAVSO. "Determining

(Continued from page 8)

4

Astronomers Agog Over Stellar Explosion By Robert Naeye, Skypub.com

The astronomical community is abuzz with activity following the closest long-duration gamma-ray burst (GRB) observed since 1998. Major telescopes on the ground and in space are being trained on the source. Research astronomers have high hopes that further study of this event will provide crucial details about the connection of long GRBs (extraordinarily powerful bursts of very-high-energy radiation that last several seconds to several minutes) to supernovae (the explosions of massive stars). Ad-vanced amateur astronomers will monitor the explosion's ex-panding fireball, which should brighten to about 16th magnitude over the next one to two weeks. NASA's Swift satellite detected the GRB at 3:43:30 Universal Time on February 18th. In less than 3 minutes Swift's Ultravio-let/Optical Telescope slewed to the correct coordinates, in the constellation Aries, and found the afterglow of the burst. As-tronomers all over the world were alerted, and an armada of telescopes began to observe the fading afterglow. At first the burst appeared rather strange because it lasted for about 30 minutes, which is 100 times longer than a typical long-duration GRB. Many astronomers wondered if it was instead a

transient object within our Milky Way Galaxy. But follow-up observations from numerous ground-based telescopes quickly associated the afterglow with a small, 20th-magnitude star-forming galaxy about 470 million light-years from Earth. Only a GRB could be so energetic to be seen by Swift at this distance. Even so, that's much closer than nearly all other GRBs. "We've been waiting several years for a nearby GRB," says Dale Frail (National Radio Astronomy Observatory), who is observing the event at radio wavelengths with the Very Large Array in New Mex-ico. On February 21st Alicia Soderberg (Caltech) and her col-leagues used the 8.1-meter Gemini South telescope in Chile to find the emerging light of a supernova (named SN 2006aj) at the exact coordinates of the GRB, and the su-pernova's light now outshines the fading GRB afterglow. The contemporaneous supernova confirms the prevailing theory for long-duration GRBs: that they occur when massive stars explode as supernovae and channel some of the energy into ejecta moving at nearly the speed of light.

Most GRBs detected by Swift occur at distances of billions of light-years. The only GRB with a closer con-firmed distance was observed by the Italian-Dutch BeppoSAX satellite on April 25, 1998, at a distance of about 120 million light-years. That event was also associated with a supernova (SN 1998bw), and was one of the crucial events that bolstered the idea that long GRBs are linked to supernovae. Both the April 1998 and February 2006 events were 10 to 100 times less energetic that most observed GRBs (despite the February 2006 event's long duration). In fact, both would have been invisible if they had occurred billions of light-years away. "This new discovery confirms that there is an underlying popula-tion of sub-energetic bursts," says Soderberg. Satellites such as Swift can only detect these low-luminosity GRBs if they occur relatively nearby. "If this were a normal GRB at that distance," adds Frail, "it would have blown out every detector in space."

(Continued on page 8)

This artist's conception depicts the violent pair of jets emitted by a typical gamma-ray burst (GRB). Astronomers now think that some supernovae channel some of their energy into jets of material traveling at near light speed. The GRB arises from shock waves within the jets. Click on the image for a larger view. Courtesy David Aguilar, Harvard-Smithsonian Center for Astrophysics.

The left image from the Sloan Digital Sky Survey shows a field in Aries before the February 18th GRB. The right image, from Swift's Ultraviolet/Optical Telescope, shows how the point of light associated with this stellar explo-sion outshines its entire host galaxy. Each image is 5 arcminutes across. Click on the image for a larger view. Courtesy SDSS (left); NASA / Swift / UVOT (right).

5

6

T h e C e l e s t i a l M e c h a n i c

Pluto Might Have Rings

By Ker Than, Space.com The two moons discovered around Pluto last year were likely formed from the same giant impact that cre-ated the planet’s much larger satellite, Charon, scientists say. The idea suggests that other Kuiper Belt Objects might also harbor multiple satellites and raises the possibility that Pluto is encircled by rings fash-ioned from debris ejected from the surface of the tiny moons. The two moons, called P1 and P2 for now, were discovered in May 2005 using the Hubble Space Tele-scope. Scientists now think the two moons are roughly 37 and 31 miles (60 and 50 km) in diameter. Charon has an estimated diameter of about 750 miles (1,200 km). The moons’ tiny sizes raise the possi-bility that even more satellites might be discovered around Pluto in the future. “The very small masses of P1 and P2 relative to Charon beg the question of why ... there are not more small satellites of Pluto,” a team of researchers write in the Feb. 23 issue of the journal Nature. “Perhaps there are other, still fainter satellites that escaped detection.” In tune with Charon Because of how P1 and P2 move, scientists think they were formed from the same collision that, accord-ing to the leading theory, spawned Charon. “The small moons are in circular orbits in the same orbital plane as Charon, and they are also in, or very near, orbital resonance with Charon,” said study leader Alan Stern of the Southwest Research Institute (SwRI). For every twelve orbits Charon makes around Pluto, P1 makes almost two orbits and P2 completes nearly three. This ratio would likely not be constant if P1 and P2 were merely passing objects captured by Pluto’s gravity. The most likely explanation for this arrangement, scientists figure, is that all three moons were born of the same event. Collisions between large objects helped shape many aspects of our solar system. The Moon, for example, is believed to have formed when a Mars-sized object slammed into Earth 4 billion years ago. The crash that’s thought to have created Pluto’s moons is believed to have occurred at around the same time. Scientists will get a closer look at Pluto and its moons when NASA's recently launched New Horizon mission reaches the system in 2015. Multiple systems the norm? Scientists have determined that up to a fifth or more of known Kuiper-belt objects (KBOs) harbor satellites or belong to binary systems; the new modeling suggests that there could also be numerous systems con-sisting of three, four or even more bodies grouped together. But finding these systems is difficult because of the distances involved. The Kuiper belt is a region of space populated by asteroids and comets and other rocky, icy bodies; it is located beyond Neptune, be-tween 30 and 50 AU from Earth. One AU is equal to the distance from the Earth to the Sun. “Finding small satellites around KBOs is difficult because their large distances from the Sun makes them appear very faint,” said study team member Andrew Steffl of SwRI. However, KBOs and their satellites are occasionally ejected from the Kuiper Belt and get flung closer to the Sun, where they become easier to spot. Steffl said a good way to determine whether KBOs with multiple satellites are unusual or the norm is to search for satellites around these outcasts, which are known as “Centaurs.” “We hope to use Hubble to search for faint moons around some of them,” Steffl said. The discovery of P1 and P2 also raises the intriguing possibility that impact debris from the small moons is captured by Pluto’s gravity and coalescing into rings or even arcs around the tiny planet. If confirmed, it would be the first example of a ring system around a solid body rather than a gas giant planet.

7

A cosmic-ray source uncovered

Scientists in the HESS collaboration have observational evidence of cosmic rays coming from our galaxy's center.

Liz Kruesi, Astronomy.com

Astrophysicists using the High Energy Stereoscopic System (HESS) have discovered very-high-energy gamma-ray emission from gas clouds near the Milky Way's center. The radiation is likely the result of cosmic rays (high-energy protons and other atomic nuclei) interacting with these gas clouds. This is the first time scientists have found direct evidence for recently accelerated cosmic rays. HESS scientists believe the observed cosmic-ray signature could have been produced in a

single supernova remnant.

Scientists can make direct measurements of cosmic rays only within our solar system. The source of galactic cosmic rays is still a mystery. However, when cosmic rays collide with protons in inter-stellar gas, they produce an array of particles, including pi mesons. Each neutral pi meson (one of

three flavors) decays into two gamma rays, which scientists can detect.

The HESS data show the cosmic-ray density in the galactic center significantly exceeds that in the solar neighborhood. This density difference between the galaxy's center and our solar neighbor-hood increases as scientists analyze higher-energy gamma rays. This implies the cosmic rays

have been recently accelerated, and probably in the last 10,000 years.

Two possible cosmic-ray accelerators reside in the galactic center. The first is supernova remnant Sagittarius A East, which scientists estimate is about 10,000 years old, making this an attractive

candidate. The second is the supermassive black hole Sagittarius A*, which may have been more active in the past. More observations are needed to pinpoint which is the cosmic-ray source.

HESS is an array of four gamma-ray telescopes located in Namibia, Africa. The HESS team's re-

sults can be found in the February 9, 2006, issue of Nature.

Very-high-energy gamma rays are arranged in a thick band across the Milky Way’s center. The gamma rays are likely a result of accelerated cosmic rays. HESS project

8

In the prevailing collapsar model for long GRBs, developed by Stan Woosley (University of California, Santa Cruz) and Andrew MacFadyen (now at the Institute for Advanced Study) in the early 1990s, GRBs are triggered when the core of a massive star collapses to form either a black hole or a neutron star. Infalling stel-lar gas swirls into an accretion disk around the collapsed core. Magnetic fields chan-nel some of the disk material into two counterflowing jets traveling at very near light speed. Shock waves within the jets generate the actual gamma rays, and the star itself blows apart as a supernova of either Type Ib or Ic (meaning the super-nova's spectrum lacks hydrogen, presuma-bly because the outer hydrogen-rich layers were blown off in the star's wind prior to the explosion). Both SN 1998bw and SN 2006aj are Type Ic, in accordance with the collapsar model.

But the collapsar model leaves a critical question unanswered: Why are some Type Ib or Ic supernovae accompanied by

GRBs, and others are not? Radio observations by Soderberg and her colleagues demonstrate that only about 1 percent of Type Ib and Ic supernovae are accompanied by GRBs, regardless of where the jets may be aimed. Woosley thinks the key ingredient is rotation. In a supernova with a GRB, the progenitor was spinning rapidly prior to its collapse, and the explosion somehow taps some of that rotational energy to produce the GRB. In low-luminosity GRBs such as the April 1998 and February 2006 events, most of the explosion's energy goes into making the supernova.

"These nearby events will enable us to test these ideas," says Frail, who notes that most GRBs are so far away that astronomers have no chance of seeing the accompanying supernova. "We'll learn much more from a few of these nearby events than from a large sample of far examples. We'll learn a lot about the fundamen-tal question of what types of supernovae give rise to GRBs."

"These observations will be crucial in helping us understand the gap between the ordinary supernovae that don't produce GRBs and the very energetic supernovae that do manage to give rise to gamma-ray emission," adds Soderberg.

Frail points out another bonus of this nearby GRB: Swift's quick alert allowed various telescopes to view the early rise of the super-nova. "Swift captures the instant of core collapse and slews instru-ments right there within seconds of it happening," says Frail. "This is a huge leap forward in terms of what we do today."

(Continued from page 4)

(Continued on page 3)

This half-degree-wide finder field in eastern Aries serves for nar-rowing in on the GRB's location. The box at upper right shows the area covered by the deeper close-up image below. The GRB site is at right ascension 3h 21m 39.7s, declination +16° 52' 02" (2000 coordinates). A 9.6-magnitude star lies 2' north of it. North is up and east is left. Courtesy Digitized Sky Survey.

This close-up from the Sloan Digital Sky Survey shows the burst's host galaxy, which is 20th magnitude in red light and 470 million light-years away. The frame is 4 arcminutes wide, with north up and east left. Courtesy Sloan Digital Sky Survey.

9

Micro-sats with Macro-potential

By Patrick L. Barry Future space telescopes might not consist of

a single satellite such as Hubble, but a constellation of dozens or even hundreds of small satellites, or “micro-sats,” operating in unison. Such a swarm of little satellites could act as one enormous telescope with a mirror as large as the entire constellation, just as arrays of Earth-bound radio telescopes do. It could also last for a long time, because damage to one micro-sat wouldn’t ruin the whole space tele-scope; the rest of the swarm could continue as if nothing had happened. And that’s just one example of the cool things that micro-sats could do. Plus, micro-sats are simply smaller and lighter than normal satellites, so they’re much cheaper to launch into space. In February, NASA plans to launch its first experimental micro-sat mission, called Space Technology 5. As part of the New Millennium Program, ST5 will test out the crucial technologies needed for micro-sats—such as miniature thrust and guidance systems—so that future missions can use those technologies dependa-bly. Measuring only 53 centimeters (20 inches) across and weighing a mere 25 kilograms (55 pounds), each of the three micro-sats for ST5 resembles a small television in size and weight. Normal satellites can be as large and heavy as a school bus. ”ST5 will also gather scientific data, helping scientists explore Earth’s magnetic field and space weather,” says James Slavin, Project Scientist for ST5. Slavin suggests some other potential uses for micro-sats: A cluster of micro-sats between the Earth and the Sun—spread out in space like little sensor buoys floating in the ocean—could sample incoming waves of high-speed particles from an erupting solar flare, thus giving scientists hours of warning of the threat posed to city power grids and communications satel-lites. Or perhaps a string of micro-sats, flying single file in low-Earth orbit, could take a series of snapshots of violent thunderstorms as each micro-sat in the “train” passes over the storm. This technology would combine the continuous large-scale storm monitoring of geosynchronous weather satellites—which orbit far from the Earth at about 36,000 kilometers’ altitude—with the up-close, highly detailed view of satel-lites only 400 kilometers overhead.

If ST5 is successful, these little satellites could end up playing a big role in future exploration. The ST5 Web site at nmp.jpl.nasa.gov/st5 has the de-tails. Kids can have fun with ST5 at spaceplace.nasa.gov, by just typing ST5 in the site’s Find It field.

This article was provided by the Jet

Propulsion Laboratory, California Institute of Technology, under a con-tract with the National Aeronautics

and Space Administration. The Space Technology 5 mission will test crucial micro-satellite technolo-gies.

10

AAL Astronomy Associates of

Lawrence

University of Kansas Malott Hall 1251 Wescoe Hall Dr, Room 1082 Lawrence, KS 66045-7582

Celestial Mechanic March 2006