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W.M. KECK OBSERVATORYC E L E B R A T I N G 2 0 Y E A R S O F E X P L O R I N G T H E U N I V E R S E

It has long been known that the universe is ex-panding, and for many years the question was,Would it end with a whimper or a bang?

That is, would the universe continue expanding

endlessly? Or would the gravity of its ingredientsultimately pull it back on itself into a so-called BigCrunch, perhaps generating another Big Bang?

But the revelation that the expansion is acceler-ating toppled that proposition, introducing thestudy of the universes dark driving forces.

Thats part of the mission on Mauna Kea.Just as an army needs infantry, artillery, cavalry

and engineers, astronomers marshal a variety offorces in their field.

Visible light tells only a fraction of the celestialstory, so Mauna Keas telescopes also observe ininfrared and submillimeter wavelengths (betweeninfrared and radio waves). Specialized instru-ments can further parse the picture.

The studies range from our neighboring planetsand their moons; asteroids including those thatmight someday hit Earth; so-called Kuiper Belt ob-jects like the former planet Pluto; cold, dark ob-jects called brown dwarfs that are neither planetnor star; interstellar gas and dust; the birth ofstars; massive and Earth-like planets aroundother stars; black holes; material between galax-ies; other galaxies and galactic clusters; and ob-jects near the dawn of time, some13 billion years ago.

HAWAIIS EYESON THE UNIVERSE

AS THOUGH presenting an early Christmas gift, a teamof astronomers using the Keck Observatory an-nounced in mid-December that it had found the clos-est thing yet to an Earth around another star.

Tau Ceti, a sunlike star only 12 light-years away, may havefive planets, but one of them is in the so-called Goldilockszone. This is a not-too-hot, not-too-cold niche where any waterwould be liquid.

Where life as we know it could exist.Finding an Earth-like planet around another star is the holy

grail of astronomy, says GntherH asinger, director of the Insti-

tute for Astronomy at the University of Hawaii.Extrasolar planets is really one of the hot topics nowadays,

and Keck has played a crucial role in discovering the first extra-solar planets, Hasinger said in a recent interview at his officein Manoa. For a very few cases we are actually able to see theplanet directly with the Keck telescope. You need very, veryspecial conditions, but sometimes you are lucky and you candirectly image a planet.

The holy grail is to find an Earth-like planet where we could,in principle, then fly to and have a second place to live if we de-stroy our own planet.

The search for exoplanets and ultimately a spectral analy-sis of their atmospheres for clues to life is one of a host ofgroundbreaking topics under discussion this week as the KeckObservatory celebrates its 20th anniversary. The Keck, whichbegan science operations on March 16, 1993, has played a keyrole in many areas of astronomy, from our planetary neighborsto the far reaches of the cosmos and everything in between.

As part of the anniversary observance, scientists will meet

Thursday and Friday at the Fairmont Orchid hotelin SouthKohala to mark Kecks milestones.

The two dozen speakers include three who will describeKecks adaptive optics, an innovative technique that uses alaser guide star to counter the blur of the atmosphere.

Mike Brown of Caltech, known as the planet killer for hisobservations that led to the demotion of Pluto, will talk aboutKecks views of the outer solar system.

Michael Liu of UH-Manoa will introduce the cool neighbors brown dwarfs. And Andrea Ghez of UCLA will detail thedizzying carousel of stars around the black hole at the center ofthe Milky Way.

As if to add an exclamation point on the events, a comet willappear in the evening sky. The best viewing may be tonight,when Comet Pan-STARRS appears below a thin crescent moon.

SINCE THE FIRST EXOPLANETwas detected in 1995 aroundthe star 51 Pegasi, 51 light-years away, the confirmed list hasgrown to more than 700, with thousands more candidates.

Most cannot be seen directly, so astronomers watch the hoststar wobble from the gravitation interaction. The movementcan be detected by the Doppler effect, the same phenomenonthat accounts for the different tones of a train whistle as thetrain swiftly approaches, then speeds away.

When the planet is circling the star, the star actually makesa little counteraction because in reality both are circling arounda common center of mass, which is inside the star, Hasinger

said. The star is actually moving as fast as the fastest runnerson Earth, about 10 meters per second. And for stellar measuresthis is really small, so you have to have very accurate spectro-graphs and you see this, the spectral light shifting back andforth in the spectrum.

The other technique to detecting exoplanets is a transit, likethe transit of Venusacross the face ofthe sun lastJune.

When we

are looking at some other planetary system and one of theplanets is moving in front of its star, we dont see that, but wesee it as a little dip in the light curve, Hasinger said.

Using that approach, a team of astronomers from Californiaand Hawaii estimated in January that 17 percent of sunlikestars have planets up to twice the diameter of Earth in close or-

bits. The scientists used NASAs Kepler space tele-scope to repeatedly image 150,000 stars in asmall region of the sky, looking for a dip inbrightness. The stars then were analyzed fur-ther with the Keck, fitted with a high-resolution

spectrograph, which turns a light wave into afrequency spectrum, similar to a rainbow.

THE GALAXYS central black hole isanother area where Keck has played

a crucial role, Hasinger said.When you look at the galaxy

with the naked eye, you see this

Scientists using Keck have foundthe strongest evidence yet thatthe salty ocean under the icy ex-terior of Jupiters moon Europainteracts with the surface. Thatmakes it a chemical-rich environ-ment that can be analyzed bystudying the surface.

KECKS GRAND VI EWOF SPACEThe W.M. Keck Observatory is locatedat the Mauna Kea summit, whichastronomers regard as the premierlocation for ground-based astronomicalresearch. Keck sits on a site 13,796 feetabove sea level, providing a view thatis largely unobstructed by water vapor.The dark skies with undisturbedoverhead airstream provide spectacularcelestial images.

AMAZING

DISCOVERIESThe W.M. Keck Observatoryhas been at the center of manyastronomical discoveries,including:

Domes>> Height:101 feet>> Weight: 700 tons

Telescope structures>> Height:80.7 feet>> Weight: About 300

tons

18 inches of dirt andgravel insulate the rooffrom the elements.

The steel and aluminum domeswere made in Canada, shipped inpieces and reassembled on thesummit. The telescopes structureswere made in Spain.

The telescopes rotate on a thinsheet of pressured, refrigeratedoil. It only takes a few 0.5-horse-power motors to turn the massive700-ton dome.

Laser guide starsAstronomers developed laser guidestars as part of the adaptive opticssystem, which compensates foratmospheric turbulence to createclearer images. An artificial star, createdby a laser beam, acts as a calibrationsource near an object astronomerswant to observe.Kecks scopeswere the first to be outfittedwith adaptive optics, in 1999and 2000. Lasers were

installed in 2004. Theentire adaptive opticssystem is now beingupgraded at a cost of$50 million, whichincludes a new$4 million laser.

The building has no living quarters for workers. It is self-sufficient for keepingthe telescopes running. Giant air conditioners run constantly during the day,keeping the dome temperature near freezing to reduce the chance of deforma-tion of the telescopes steel and mirrors due to fluctuating temperatures. Thisprevents air turbulence as the telescope structures and mirrors cool to night-time temperatures. Giant exhaust fans also suck air through the domes whenthey are open. This prevents any heat sources, including human bodies, fromcreating air turbulence that might disrupt viewing.

Lower shutter

Uppershutter

Astronomers use the telescopes inshifts of one-half to five nights. Timeallocation committees pre-approveall observing. Assistants operate thetelescopes at the summit whileastronomers gather data via remoteobserving from observatoryheadquarters in Waimea.

Wind screen

KECK IFirst science observations in 1993

HAWAII

2 Submillimeter ArrayEXTREMELY DETAILED EXPLORATION

The Submillimeter Array, or SMA, is an

eight-dish microwave observatory operatedjointly by the Smithsonian Astrophysical Obser-vatory in Cambridge, Mass., and Taiwans Academia

Sinica Institute of Astronomy and Astrophysics. Five ofthe dishes are shown at left.>> Completed: 2002

>> Highlights: Submillimeter astronomy picks up low-energysignals from the microwave part of the spectrum. Each dish, 20 feetin diameter, has four receivers, two of which can work simultane-

ously to pick up emissions from extremely cold and dark inter-stellar gas and dust, star-forming molecular clouds in our

own and distant galaxies, rapidly receding galaxies andthe center of the Milky Way. The dishes also can work

in unison with telescopes all over the world to sim-ulate an Earth-size telescope in what is known

as Very Long Baseline Interferometry. In 2006the array became the first telescope of its

kind to see Pluto and its moon Charonas separate objects.

1 Subaru TelescopeHUNTING FOR EARTH-LIKE PLANETS

Japans Subaru Telescope is an optical-infrared telescope that uses an 8.2-meter (27-

foot) curved mirror and advanced technologiesto study objects at the far reaches of the solar sys-

tem, comets, small asteroids between Mars and Jupiter,the birth of stars and planetary systems, quasars and

galaxies.>> Completed: 1999

>> Highlights: Subaru is the Japanese name for the constellationPleiades or Seven Sisters (Makalii, or little eyes, in Hawaiian).

Cameras and spectrographs can be mounted at the telescopesfour focal points for observations in visible and infrared

(heat) wavelengths. One specialty is the direct imaging of

planetary systems around other stars. Last June, ateam of astronomers used the Subaru and Keck tel-

escopes to discover the most distant galaxy yetfound, SXDF-NB1006-2, at a distance of 12.91

billion light-years from Earth. It wasslightly farther than a galaxy found

with the Subaru the previous year.

3 NASA Infrared Telescope FacilityOBSERVING THE SOLAR SYSTEM

This 3-meter telescope, optimized for in-frared observations, is operated and man-

aged for NASA by the University of HawaiiInstitute for Astronomy. NASA provides operating

costs, and the National Science Foundation providesfunding for new instrumentation.>> Completed: 1979

>> Highlights: Observing time is open to the entire astronomi-cal community; 50 percent of that time is reserved for studies ofsolar system objects. A high-speed Internet connection lets ob-

servers use the facility from any location, such as their office orhome. One of the facilitys specialties is the analysis of plan-

etary surfaces and atmospheres, such as searching formethane on Mars and observing seasonal cloud activ-

ity on Saturns moon Titan. The facility is alsostudying the composition of asteroids that

come close to Earth. Observations of Plutohave revealed perplexing variations in

the abundance of methane, carbonmonoxide and frozen nitrogen.

4 James Clerk Maxwell TelescopeSURVEYING GAS AND DUST IN GALAXIES

The James Clerk Maxwell Telescope,commonly referred to as the JCMT, is the

largest observatory in the world designed to op-erate at submillimeter wavelengths. It is run by the

United Kingdom, Canada and the Netherlands, but thepartnership will end on Sept. 30, 2014, leaving its fate un-

certain.>> Completed: 1987

>> Highlights: Named after the Scottish physicist who discov-ered that electricity, light and magnetism are facets of the same

phenomenon, the JCMT, with a diameter of 49 feet, detects sub-millimeter radiation to study our solar system and interstel-

lar gas and dust. As part of the SCUBA-2 Legacy Survey, ateam of more than 100 astronomers is mapping the

sky to find rare distant galaxies, sites of star forma-tion, and stars hosting planetary systems. Last

year the JCMT became the first submillime-ter telescope in the world to observe the

transition between night- and day-sidewinds on Venus.

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KECK IIFirst scienceobservationsin 1996

W.M. KECK OBSERVATORY

Sources: California Association for Research in Astronomy; Air & Space Magazine;spaceftkits.com/KFacts2.html; amazing-space.stsci.edu; keckobservatory.org

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as a bright, white light, he said. But in between are gas and dustclouds that are actually blocking our view of the center of thegalaxy. But when you have infrared eyes, you can actually lookthrough these gas and dust clouds.

There resides an intriguing cluster of stars, 100 or so, all veryyoung, on the order of 2 million years old the same age as theisland of Maui, he said.

These stars are moving around in regular patterns, they movein ellipsis and they move around an empty spot, which is basi-cally the black hole, Hasinger said. And from these movementsyou can determine there must be a very massive heavy object,

which is 3.5 million solar masses, which slings around the starswith very fast motions about 10,000 kilometers a second or so(22.4 million mph), so its really a very powerful thing that cansling around a whole star.

While the black hole is not directly observable its intensegravity keeps even light from escaping its grip every now andthen it offers up an X-ray burst.

It seems to take a small snack of some material, maybe a gascloud or maybe an asteroid, something that is falling on it, and itflares up for a short period of time, said Hasinger. It is usuallystarving, but every once in a while it gets a snack and does a hic-cup.

Astronomers agree that the key to success for any observa-tory, Keck included, is instrumentation, which can give even anold dog a set of new tricks.

The growth of technology gives telescopes a new life ondecade time scales expanding the parts of the spectrum theycan observe, multiplying the number of objects we can target atonce, correcting for atmospheric blurring over bigger and biggerareas, said UH astronomer Roy Gal.

One can only wonder how Keck will celebrate 40.

KECK II36 segments

KECK I36 segments

72 segmentsof surface area for

light collection

BIGGER VIEW

Combining the power of bothtelescopes increases resolutionas if there were a mirror with adiameter as big as the diameterof both Kecks plus the distance

between them. To accomplishthis feat, light is picked off eachtelescopes tertiary mirror, and itfollows additional mirrors alonga path (shown below in red) tothe beam-combining room in theobservatorys basement.

KECK IIKECK I

MIRROR SEGMENT

36 hexagonal mirrors make up the primarymirror with a diameter of 33 feet. Theindividual mirrors are:

>> Diameter:6 feet>> Weight: 880 pounds>> Thickness:3 inches>> Cost: $800,000>> Space between segments: 3 millimeters>> Glass makeup: Zerodur, part glass and

part ceramic

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Secondary mirrorsupported by spider

Tertiary mirror:Rotates atoptower to sendlight to variousinstruments

36-segmentprimarymirror

INCOMING LIGHT

Whiffletree:Branchesout to all corners ofthe segment

Flex disk: Allowsup-and-down motion,but restricts motionfrom side to side

Upper telescopetube supports spider

Nasmythplatform

WEDNESDAY 3/13/13

TWO IS BETTER THAN ONE

Light-collecting increases as if the surface areasof all the segments were being added together:

Adding togetherthese three

distances resultsin an effectiveresolution of a

mirror this large.

Distance betweentelescopes

Elevationring

2.2 pt

ACTUATOR

Three actuators independently adjust the mirror. Anencoder receives commands from the main com-

puter, then activates the motor that turns the shaft.The shaft turns the reduction gear and bellows. Thebellows turn a shaft that raises and lowers the mirror.

>> Shaft that connects to whiffletree moves up ordown in increments of 4 nanometers.

>> Computer-driven servo motor turns a screw asoften as twice per second. Screws pitch is onethread per millimeter.

1. Incoming starlight on its way to the primarymirror.

2. Light is reflected off the primary mirror towardthe secondary mirror, bouncing off thesecondary.

3. Light is reflected back down toward the tertiarymirror.

4. Light is reflected off the tertiary mirror to aninstrument at one of the Nasmyth foci.

HOW KECK WORKSKecks telescopes mirrors are a collective of 36 unique hexagonal segments, making them the largest astronomical mirror in the world.Astronomers can adjust each mirror segment individually to control distortion. This adjustment system is called a whiffletree, an oldword that describes the crossbars used to hitch horses to a wagon.

Shaft

Encoder tocomputer

Hydraulicbellows

Reductiongear

9 United Kingdom Infrared TelescopeSURVEYING DEEP SPACE

With a mirror spanning 3.8 meters(150 inches), this is the largest telescope in

the Northern Hemisphere dedicated solely to in-frared astronomy. But the British Science and Tech-

nology Facilities Council has encountered a fundingcrunch and will either close the facility or transfer opera-

tions to another entity by the end of 2013.>> Completed: 1979

>> Highlights: The telescopes main instrument, the UKIRT Wide-Field Camera, has been used primarily to carry out the Infrared

Deep Sky Survey, a colossal inventory of the northern sky. Thesurvey, which began in 2005, looked for the coolest and

nearest brown dwarfs, rapidly receding dusty starburstgalaxies, elliptical galaxies and galactic clusters, and

the most rapidly receding quasars. The surveyalso aimed to discover the nearest objects to

the sun outside the solar system as well assome of the farthest known objects in the

universe. In 2011, the survey found themost distant quasar on record.

10 UH-Hilo Educational TelescopeHANDS-ON TRAINING

The dome that used to house the Uni-versity of Hawaiis 24-inch telescope now has

a 36-inch mirror used for training astronomy ma-jors at the University of Hawaii at Hilo.>> Completed: 2010

>> Highlights: Renovations to the observatory upgradewere finished in October 2008, and the new 36-inch tele-

scope, Hoku Kea, was installed in October 2010. It becamepartly operational in the fall of 2011, but the staff is still dealing withsoftware problems. The telescope, controlled remotely from the

UH-Hilo Sciences and Technology Building, can conduct wide-field imaging surveys for extrasolar planets, supernovae and

other targets.

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8 UH 2.2-Meter TelescopeDISCERNING SPACE ROCKS NEAR AND FAR

The University of Hawaii 2.2-Meter (88-inch) Telescope was the first large telescope

built on Mauna Kea and showed the world the sitewas one of the best for astronomy. The facility was a

leader in the development and use of infrared arrays andcharge-coupled devices, now used in digital cameras.

>> Completed: 1970>> Highlights: The UH Institute for Astronomy says the most

important discovery made with the telescope is the existence of theKuiper Belt in the outer part of the solar system. Before 1990, the

only known object (other than comets) beyond the orbit of Nep-tune was Pluto. But the UH telescope showed that the region

hosts countless asteroid-size bodies now called KuiperBelt objects. The first was discovered in 1990 by UH

astronomers Dave Jewitt and Jane Luu. More re-cently, UH asteroid hunter David Tholen used

the telescope to calculate the odds of the as-teroid Apophis hitting Earth in 2036. The

answer: very low.

7 Gemini ObservatoryTWIN PEEKS

The Gemini Observatorys identical8.1-meter (27-foot-diameter) optical-infrared

telescopes on Mauna Kea and in the ChileanAndes provide full-sky coverage and explore the

universe with state-of-the-art instruments and technolo-gies. Gemini is operated by a partnership of the United

States, Canada, Chile, Australia, Brazil and Argentina.>> Completed: 1999

>> Highlights: The Frederick C. Gillett Gemini North telescope,with headquarters at the University of Hawaii at Hilos University

Park, uses a suite of advanced technologies to deliver high-quality images, including laser guide stars and adaptive op-

tics that correct for the blur of the atmosphere. In 2008,

astronomers using Gemini were the first to directlyimage a planet around a sunlike star, a finding that

was confirmed two years later. Also in 2008, as-tronomers using Gemini and the Keck got

the first direct images of a multiplanetsystem around a normal star.

6 CalTech Submillimeter ObservatoryASSESSING THE MATTER BETWEEN STARS

The California Institute of Technologyoperates this 10.5-meter (34-foot-diameter)

telescope through an agreement with the Na-tional Science Foundation. Like its neighbors, the

Maxwell telescope and Submillimeter Array, the obser-vatory picks up radiation from celestial objects in a spec-

tral range that is important to the study of interstellar matter.>> Completed: 1987

>> Highlights: The observatory is used to study the chemistryof interstellar gas, the conditions surrounding star birth, the late

stages of stellar evolution and the history of star formation. Be-cause atmospheric water vapor interferes with submillime-

ter observations, the observatory is high on Mauna Keato take advantage of the dry conditions. Most observa-

tions are made at night when the atmosphere is dri-est and most stable. Among the observatorys

accomplishments are determining the role ofatomic carbon in the interstellar medium

and the first ground-based detectionof heavy water in a comet.

5 Canada-France- Hawaii TelescopeWIDE-FIELD IMAGING IN VISIBLE LIGHT

As its name implies, this telescope is ajoint operation run by the national research

centers of Canada and France, along with theUniversity of Hawaii. It uses a 3.6-meter (11.7-foot-di-

ameter) mirror for optical and infrared observations.>> Completed: 1979

>> Highlights: Once one of the largest telescopes in theworld, the Canada-France-Hawaii facility uses state-of-the-art in-

strumentation to stay at the forefront of astronomy. One instrument,MegaCam, is used in a wide range of studies, including Earth-ap-

proaching asteroids, remote galaxies and large-scale structuresin the universe. The telescope also contributes to the study

of mysterious dark matter and dark energy. The telescoperecorded the first images of gravitationally lensed dis-

tant galaxies their light curved by the gravity ofgalactic clusters. Measurements made at the tel-

escope in the early 1980s were among thefirst to pin down exactly how much regu-

lar matter (as opposed to dark matter)exists in the universe.

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Beam-combining room

Two super-luminoussupernovae stellarexplosions 10 to 100 timesbrighter than other supernovatypes have been detected inthe distant universeusing Keck.The discovery sets a record forthe most distant supernovaeyet detected and offers the rarepossibility of observing theexplosions of the first stars toform after the Big Bang.

Adaptive optics on Keck haveallowed astronomers to find ablack hole at the center of theMilky Way. It is now understoodthat all galaxies have aproportionately sized black hole intheir centers. At left, the galacticcenter without adaptive optics. Atright, the galactic center andcentral black hole with adaptiveoptics.

Geoff Marcy of theUniversity of California,Berkeley, discovered the firstplanet outside our solarsystem by employing theDoppler effect in spectroscopy.The first image of an exoplanetwas done with Keck, and todaymore than 1,000 suchdiscoveries later, Keck hasfound the majority of all knownexoplanets.

BLACK

HOLE

W.M. KECK OBSERVATORY

W.M. KECK OBSERVATORY

W.M. KECK OBSERVATORY

W.M. KECK OBSERVATORY AND UCLA GALACTIC CENTER GROUP