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Calendar of Events Spring Meeting Schedule

FRIDAY MAY 11 1001 Malott Hall, KU

7:30 PM ASTRO IMAGING

DAVID KOLB Kansas City Kansas Community College

President: Luis Vargas lcvargas@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 Observing Clubs Doug Fay dfay@ku.edu

Report from the Officers on the APRIL Meeting:

MAY 11—7:30 PM WE’RE BACK!!!!!!!!!!!!

The last few months have been hectic and a bit ruinous to our usual meeting schedule, but good things come to those who wait. We will have our last meeting of the semester on May 11 and , after a three month delay, we will finally get to see the

presentation by David Kolb on his extraordinary techniques for imaging the sky, (Continued on page 2)

Volume 33 Number 05 May 2007

INSIDE THIS ISSUE

From the Officers (continued) 2

Extrasolar Water 3

NASA Space Place 4

Meeting Poster: Dave Kolb 5

The Wake of a Dying Star 6

Black Holes not so Bad 6

The Sun in STEREO 7

A Nearby Quasar 8

Two Great Astronomers Pass 9

Obituaries (continued) 8

Of Local Interest From Science News,

Northern Exposure: The inhospitable side of the galaxy? Davide Castelvecchi

The solar system's periodic visits to the northern side of the Milky Way ex-pose life on Earth to extra cosmic rays that have caused catastrophic mass

extinctions, two astrophysicists propose.

Biodiversity has had well-known ups and downs over the eons, with major extinctions followed by rebounds. In a 2005 study, Robert Rohde and Richard

Muller of Lawrence Berkeley (Calif.) National Laboratory found that these swings were surprisingly regular, most of them taking place at intervals of

about 62 million years. The researchers reached their conclusion after exam-ining one of the most comprehensive long-term biodiversity surveys, a compi-

lation of fossil data that charted the number of marine-life genera over the past 500 million years.

The extraordinary dinosaur kill 65 million years ago doesn't fit in the cyclic pattern, and experts widely blame it on the impact of a large asteroid.

To explain the cyclic pattern of mass extinctions, Rohde and Muller consid-ered a phenomenon that has just about the right periodicity. As the solar sys-tem orbits around the galaxy, it swings from one side to the other of the galac-tic plane every 63 million years. Gravity from the rest of the galaxy's mass pulls the solar system back each time.

Perhaps when the sun is at the maximum distance from the galactic plane, Earth's biodiversity is at greatest risk, Rohde and Muller speculated. But that would put mass extinctions every 31.5 million years, not every 63 million. It wasn't clear why one side of the galaxy's plane would be more dangerous to life than the other.

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using both stills and video. This time snow is unlikely and no external speakers of astrophysical interest are scheduled on or off campus. So, please come out to hear what Dave has to say and take part in planning any events for the sum-mer. We would like to schedule some summer observing downtown for after the Wed. evening band concerts, but what we do is up to you.

The major astrophysics event of April was the MidAmerican Regional Astrophysics Conference in Kansas City on April 13/14. The meeting had record attendance with a full schedule of talks, but a highlight was the public lecture by Dr. Alan Hirshfeld, author of the book “Parallax: The Race to Measure the Cosmos” , speaking at UMKC about his recently released and very well reviewed book “The Electric Life of Michael Faraday”. Al is a very thoughtful and en-gaging speaker who had an extraordinary subject to work with, Michael Faraday, possibly the greatest experimental physicist of the 19th century who had no formal training in math or physics. There are still a few signed copies of the

book available for purchase; if interested, contact Bruce Twarog at btwarog@ku.edu.

Our final Memorial Stadium observing session of the year took place on Sunday April 29 from 9:00—10:30 PM. While the moon was a bit bright, the weather conditions were exceptional, warm and comfortable with clear skies. The public who showed up stayed almost the entire time and, at some point, we literally ran out of objects that were easily identifiable with the bright sky. Many thanks to Rick Heschmeyer and William Winkler for their help with the telescopes and keeping the public informed about what they were viewing.

COMING EVENTS: In the Region: The Mid-States Regional Astronomical League (MSRAL) Convention 2007 will be held in Omaha, NE on June 8 and 9, 2007, at the Westside Community Conference Center. For details and info, check out their web site at www.omahaastro.com/msral2007.

The Heart of America Star Party, run by the Astronomical Society of KC, is scheduled for June 12-17. Detailed info on the event can be found at www.hoasp.org or by contacting Dan Johnson at gdj102356@hotmail.com. Brochures are also available for the Nebraska Star Party, scheduled for July 15-20, 2007 near Valentine, NE. The web site for this event is www.NebraskaStarParty.com.

A little farther afield is the Green Bank Star Quest—it takes place on July 4-7 at Green Bank Observatory in West Virginia. I’ve included announcement sheets in the newsletters for some of the members; if there isn’t one attached to your newsletter, but you would like to know more, visit their web site at www.greenbankstarquest.org for more info and registration. They have a first class set of speakers for the event.

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 at the meeting next week.

ALL for now.

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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:Luis Vargas at lcvargas@ku.edu, Gary Webber at gwebber@ku.edu, our faculty advisor, Prof. Bruce Twarog at btwarog@ku.edu. 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

2006 on the CloudSat QuickLook website at cloudsat.atmos.colostate.edu. And to introduce kids to the fun of observing the clouds, go to spaceplace.nasa.gov/en/kids/cloudsat_puz.shtml.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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Mikhail Medvedev and his colleagues of the University of Kansas in Lawrence now propose an explanation that rests on variations in the number of high-energy particles, known as cosmic rays, that strike Earth from space. They argue that because the galaxy is moving toward a large cluster of galaxies in the direction of the Virgo con-stellation, cosmic rays would be more abundant on the galaxy's north side—according to the view from Earth.

A particle flow similar to the solar wind emanates from the Milky Way as a whole, and as the galaxy moves, that wind runs into the tenuous medium that pervades intergalactic space. The collision creates a shock wave. The Kansas team calculates that when electrically charged particles rebound within the shock wave, they gain enough energy to turn into cosmic rays. When a cosmic ray hits the upper layers of the atmosphere, it triggers a shower of millions of energetic electrons and other particles, some of which can penetrate to land and into the oceans. The particles have a variety of effects. For example, they may alter cloud coverage or damage DNA, with potentially fatal consequences for entire species.

"Drops in biodiversity correspond to peaks in cosmic rays," Medvedev says. However, he and his colleagues stress that they haven't identified the mechanism linking cosmic rays and extinctions.

"I was stunned when I learned that [Medvedev's team] had succeeded where we had failed" at explaining the 62-million-year cycle, Muller says.

Charles Dermer, an astrophysicist at the Naval Research Laboratory in Washington, D.C., says that the new explanation is "very tantalizing" but that it rests on Rohde and Muller's biodiversity cycles, which are not firmly established. Medvedev and his colleagues say that the cosmic ray bombardments would also increase gamma rays from the north side of the galaxy, a prediction that new gamma-ray observatories may test in the next few years.

The researchers presented their work this week, in Jacksonville, Fla., at a

meeting of the American Physical So-ciety. The report is also due to appear

in Astrophysical Journal.

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COSMIC PERIL. As the Milky Way (represented here by a similar gal-axy) whirls around, the solar system's wobbly trajectory (green curve) periodically exposes Earth to harsh cosmic rays. The white dashed line shows the sun's motion as it would appear in the plane of the galaxy. Medvedev/ Univ. of Kansas

Water is Found in Extrasolar Planet's Air United Press International

U.S. astronomers have, for the first time, identified water in the atmosphere of an extrasolar planet. The identifica-tion was accomplished using Hubble Space Telescope measurements and theoretical models developed by Lowell Observatory astronomer Travis Barman. He found strong evidence for water absorption in the atmosphere of transiting planet HD209458b.

We now know that water vapor exists in the atmosphere of one extrasolar planet and there is good reason to be-lieve that other extrasolar planets contain water vapor, said Barman. Although water vapor has been expected in the atmospheres of nearly all known extrasolar planets, most are too close to their parent star to allow identifica-tion. The identification involving planet HD209458b was made possible since, as seen from Earth, it periodically passes in front of its star. As it does so, its atmosphere blocks a different amount of the starlight at different wave-lengths.

An analysis of Hubble data by Harvard University student Heather Knutson made possible a direct comparison to theoretical models developed by Barman. That ultimately led to the identification of water absorption on the planet 150 light-years from Earth. The research has been accepted for publication in the Astrophysical Journal.

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Clouds from Top to Bottom

By Patrick L. Barry

During the summer and fall of 2006, U.S. Coast Guard planes flew over the North Pacific in search of illegal, unli-censed, and unregulated fishing boats. It was a tricky operation—in part because low clouds often block the pilots' view of anything floating on the ocean surface below. To assist in these efforts, they got a little help from the stars.

Actually, it was a satellite—CloudSat, an experimental NASA mission to study Earth’s clouds in an entirely new way. While ordinary weather satellites see only the tops of clouds, CloudSat’s radar penetrates clouds from top to bottom, measuring their vertical structure and extent. By tapping into CloudSat data processed at the Naval Research Labo-ratory (NRL) in Monterey, CA, Coast Guard pilots were better able to contend with low-lying clouds that might have otherwise hindered their search for illegal fishing activity.

In the past, Coast Guard pilots would fly out over the ocean not knowing what visibility to expect. Now they can find out quickly. Data from research satellites usually takes days to weeks to process into a usable form, but NASA makes CloudSat's data publicly available on its QuickLook website and to users such as NRL in only a matter of hours—making the data useful for practical applications.

"Before CloudSat, there was no way to measure cloud base from space worldwide," says Deborah Vane, project manager for CloudSat at NASA's Jet Propulsion Laboratory.

CloudSat’s primary purpose is to bet-ter understand the critical role that clouds play in Earth's climate. But knowledge about the structure of clouds is useful not only for scientific research, but also to operational users such as Coast Guard patrol aircraft and Navy and commer-cial ships at sea.

“Especially when it's dark, there’s limited information about storms at sea,” says Vane. “With CloudSat, we can sort out towering thunderclouds from blankets of calmer clouds. And we have the ability to distinguish between light rain and rain that is falling from severe storms.” Cloud-Sat’s radar is much more sensitive to cloud structure than are radar systems operating at airports, and from its van-tage point in space, Cloudsat builds up a view of almost the entire planet, not just one local area. “That gives you weather information that you don't have in any other way.”

There is an archive of all data collected since the start of the mission in May

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A CloudSat ground track appears as a diagonal line overlaid upon a GMS-6 (a Japanese weather satellite) infrared image. CloudSat is crossing the north-central Pacific Ocean on a descending orbit (from upper-right to lower-left) near a storm front. The radar data corresponding to this ground track (beginning in the center panel and continuing into the lower panel) is output in color and shows a vertical cloud profile far more complex than the two-dimensional GMS-6 imagery would suggest.

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Dying Sun-like Stars Leave Whirlpools In Their Wake

Science Daily — Astronomers based at Jodrell Bank Observatory have found evidence that giant whirlpools form in the wake of stars as they move through clouds in interstellar space.

Dr Wareing and his colleagues used the COBRA supercomputer to simulate in three-dimensions the movement of a dying star through surrounding interstellar gas. At the end of their life, Sun-sized stars lose their grip on their outer layers and as much as half of their mass drifts off into space. The computer simulation modelled the collision between material given off by the star and the interstellar gas.

It showed that a shockwave forms ahead of the dying star and giant eddies and whirlpools develop in the tail of mate-rial behind the star, similar to those seen in the wake of boats on open water. The group have now backed up these predictions with observations of the planetary nebula Sharpless 2-188 taken as part of the IPHAS (Isaac Newton Telescope Photometric H alpha Survey of the Northern Galactic Plane).

The central star of Sharpless 2-188 is 850 light years away and it is travelling at 125 kilometres per second across the sky. Observations show a strong brightening in the direc-tion in which the star is moving and faint material stretching away in the opposite direction. Dr Wareing believes that the bright structures in the arc observed ahead of Shar-pless 2-188 are the bowshock instabilities revealed in his simulations, which will form whirlpools as they spiral past the star downstream to the tail.

"These vortices can improve the mixing of the stellar mate-rial back into interstellar space, benefiting the next cycle of star formation. The turbulent whirlpools have an inherent spin, or angular momentum, which is an essential ingredi-ent for the formation of the next generation of stars." said

Dr Wareing who developed the computer model during his PhD and is now using it to understand the fate of our Sun. Dying stars eject both gas and dust into space. The dust will coalesce into planets around later generations of stars. The gas contains carbon, necessary for life and produced inside stars. How the carbon, other gas and dust are ejected from the dying star is not well understood. The whirlpools in space can play an important role in mixing these essential ingredients into the interstellar gas from which further stars and planets will form.

This discovery was presented by Dr Chris Wareing at the Royal Astronomical Society’s National Astronomy Meet-ing in Preston.

A combined image showing the bright regions and the faint regions behind the bright arc. (Credit: Image credit: N Wright, University College London)

Black holes: Not the villains we thought?

A Mexican-led team of astronomers said black holes might not be the ultimate destroyers as they are often por-trayed. Instead, warm gas escaping the clutches of the enormous black holes might be a source of the chemical elements that make life possible.

The researchers, led by Yair Krongold of the National Autonomous University of Mexico, said the universe, imme-diately after the Big Bang, contained only hydrogen and helium. Heavier chemical elements had to be developed in the first stars and scattered throughout space to be incorporated in next-generation stars and their planets. Black holes, the researchers said, might have helped to distribute those elements across the cosmos.

"One of the big questions in cosmology is how much influence massive black holes exert on their surroundings," said study co-author Martin Elvis of the Harvard-Smithsonian Center for Astrophysics. "This research helps an-swer that question."

The astronomers determined hot winds from giant black holes in galactic centers may blow heavy elements such as carbon and oxygen into the vast tracts of space between galaxies.

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NASA Spacecraft Make First 3-D Images Of Sun Science Daily — NASA's twin Solar Terrestrial Relations Observatory (STEREO) spacecraft have made the first three-dimensional images of the sun. The new view will greatly aid scientists' ability to understand solar physics and thereby improve space weather forecasting.

“3-D view is like going from a regular X-ray to a 3-D CAT scan in the medical field," said Michael Kaiser, the mission's project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. The spacecraft were launched October 25, 2006. On January 21 they com-pleted a series of complex maneuvers, including flying by the moon, to position the spacecraft in their mission orbits. The two observatories are now orbiting the sun, one slightly ahead of Earth and one slightly behind, separating from each other by approximately 45 de-grees per year. Just as the slight offset between a per-son's eyes provides depth perception, the separation of spacecraft allows 3-D images of the sun. The new 3-D images are generated by NASA's Jet Propulsion Labo-ratory, Pasadena, Calif.

Violent solar weather originates in the sun's atmos-phere, or corona, and can disrupt satellites, radio com-munication, and power grids on Earth. The corona re-sembles wispy smoke plumes, which flow outward along

the sun's tangled magnetic fields. It is difficult for scientists to tell which structures are in front and which are be-hind.

"In the solar atmosphere, there are no clues to help us judge distance. Everything appears flat in the 2-D plane of the sky. Having a stereo perspective just makes it so much easier," said Russell Howard of the Naval Research Laboratory, Washington, the principal investigator for the Sun Earth Connection Coronal and Heliospheric Inves-tigation suite of telescopes on the spacecraft. "With STEREO's 3-D imagery, we'll be able to discern where mat-ter and energy flows in the solar atmosphere much more precisely than with the 2-D views available before. This will really help us understand the complex physics going on," said Howard.

The mission's depth perception also will help improve space weather forecasts. Of particular concern is a de-structive type of solar eruption called a coronal mass ejection. These are eruptions of electrically charged gas, called plasma, from the sun's atmosphere. A coronal mass ejection cloud can contain billions of tons of plasma and move at a million miles per hour.

Such a cloud is laced with magnetic fields, and coronal mass ejections directed toward Earth smash into our planet's magnetic field. If the coronal mass ejection magnetic fields have the proper orientation, they dump en-ergy and particles into Earth's magnetic field. This causes magnetic storms that can overload power line equip-ment and radiation storms that disrupt satellites.

Satellite and utility operators can take precautions to minimize coronal mass ejection damage, but they need an accurate forecast of when one will arrive. To do this, forecasters need to know the location of the front of the cor-onal mass ejection cloud. STEREO will allow scientists to accurately locate the cloud front. "Knowing where the front of the CME [coronal mass ejection] cloud is will improve estimates of the arrival time from within a day or so to just a few hours," said Howard. "STEREO also will help forecasters estimate how severe the resulting mag-netic storm will be."

"In addition to the STEREO perspective of solar features, STEREO for the first time will allow imaging of the so-lar disturbances the entire way from the sun to the Earth. Presently, scientists are only able to model this region in the dark, from only one picture of solar disturbances leaving the sun and reaching only a fraction of the sun-Earth distance," said Madhulika Guhathakurta, the mission's program scientist at NASA Headquarters, Washing-ton.

Note: This story has been adapted from a news release issued by NASA/Jet Propulsion Labo-ratory.

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

year battle with brain cancer.

Paczynski died Thursday at the age of 67, it was announced Tuesday.

The Princeton University scientist's pioneering efforts to develop the technique called gravitational lensing permitted the discovery of the first terrestrial planet found outside our solar system. Despite widespread skepticism from other astrophysicists, he also championed the idea the still-mysterious events known as gamma ray bursts originated bil-lions of light-years away rather than within the Milky Way galaxy. His theory was ultimately confirmed by observa-tions.

He was incredibly creative and original, said Michael Strauss, a Princeton professor of astrophysical sciences. All his life he brought interesting approaches to interesting problems. Paczynski received many honors during his career, including the Gold Medal of the Royal Astronomical Society and the 2006 Henry Norris Russell Lectureship, the high-est award of the American Astronomical Society. He was a member of the Polish Academy of Sciences and the U.S. National Academy of Sciences.

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Harvard Scientists Find Quasar in Nearby Galaxy By Diane J. Choi, Harvard Crimson ( Harvard )

For a team of Harvard University astrophysicists who gazed into other galaxies last April, the stars must have been favorably aligned. That team, led by researcher Guido Risaliti, witnessed the eclipse of a supermassive black hole in the center of a nearby galaxy, according to a study published in The Astrophysical Journal last week.

The term black hole is misleading in the case of this galaxy, known as NGC 1365, which has a brightly lit core instead of a dark one. The galaxy's center -- known by scientists as a nucleus -- emits light and radiation due to the powerful gravitational field of the black hole, and is better known as a quasar.

"Quasars light up because gas is falling down toward them, which heats up through friction like a rocket reentering the atmosphere," said Martin S. Elvis, a senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics and a co-author of the study.

This region of super-heated gas, Elvis said, is shaped like a disk in NGC 1365's quasar and is a source of X-ray radia-tion. But scientists had been unable to determine the precise location of this hot gas disk before Risaliti's experiment. Risaliti -- who is also a visiting astrophysicist at the CFA -- and his colleagues decided to delve deeper into the peri-odic eclipses of the NGC 1365 quasar's emissions.

Such eclipses are caused by clouds of gas that drift around the black hole, occasionally blocking X-ray radiation from reaching the earth. A series of six observations of NGC 1365, made every two days over a period of two weeks in April 2006, happened to coincide with one such eclipse.

"In two days, it went from being shining bright to being very dark, then back to being bright again," Elvis said. The eclipse had occurred for a much shorter time span than expected, compelling Risaliti and his colleagues to reach an unexpected conclusion.

"Originally the idea was that these gas clouds were a long way out, and so would take a long time to cover up the X-ray source," Elvis said. "Now it's so close, it's almost ridiculous."

Their observations confirmed one structural model for quasars. The cloud that had eclipsed the X-ray source was found to be a mere hundredth of a light year from the black hole's event horizon, or the point at which material is per-manently consumed by the black hole. Since these clouds surround the emission source, it is now known to be ex-tremely close to the black hole as well.

"People have been trying to understand quasars and active nuclei for many years now," said Giuseppina Fabbiano, an associate at the Harvard Observatory and another co-author of the study. "This is the first time that we can say with real certainty that there is emission that comes from very near [the black hole]."

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Dorrit Hoffleit, 100, wrote Yale Bright Star Catalogue By Keith O'Brien, Globe Correspondent , April 17, 2007

As a woman interested in studying the heavens, Dorrit Hoffleit never had it easy. Astronomers, for the most part, were men when Hoffleit was graduating from Radcliffe College in 1928, and her own mother didn't exactly make it easier on Dr. Hoffleit by telling her she wasn't very smart.

"No matter how dumb a man might be ," Dr. Hoffleit said in March from her apartment in New Haven, Conn., "he was pre-ferred over a mere woman."

But Dr. Hoffleit wasn't the sort to shy away from a challenge. She not only became an astronomer, she also spent almost 50

years doing research at Yale University. By the time she died at home on April 9 of complications from cancer, Dr. Hoffleit was considered the oldest active woman astronomer and perhaps the oldest active astronomer. She was 100.

"She was amazing," said Vladimir Strelnitski, director of astronomy at the Maria Mitchell Association, which has an observatory on Nantucket where Dr. Hoffleit did research and taught students from 1957 to 1978. "She was the most wholesome personality I ever met in my life. She was so dedicated to the service of society, to the field of astronomy, and to her students."

Dr. Hoffleit, the daughter of German immigrants, was born in Florence, Ala., on March 12, 1907, and grew up in New Castle, Pa., until her older brother, Herbert, was accepted at Harvard and her family moved to Cambridge to support him. Dr. Hoffleit remembered getting less support from her family. But she didn't let that get in her way Stubborn and willing to work hard, she took her undergraduate degree in mathematics and went to work as a re-search assistant in Harvard's astronomy department.

Men were paid more there than women. But Dr. Hoffleit, who never married, loved the work. The stars had fasci-nated her since she was a girl and she earned a doctorate in astronomy from Radcliffe College in 1938. She calcu-lated missile trajectories for the government during World War II and then joined Yale University 's astronomy de-partment in 1956. She remained there the next five decades. As the author of the Yale Bright Star Catalogue, she tracked stars across the sky and published their locations. In her spare time, she studied variable stars, stars that vary in brightness with time, and taught young female astronomy students on Nantucket every summer. Awards and honors began to pile up.

She was awarded the George Van Biesbroeck Prize in 1988 for dedication to astronomy and five years later the American Astronomical Society awarded her the Annenberg Prize for science education. That same year, she was inducted into the Connecticut Women's Hall of Fame. And still, though she had officially retired at age 68 in 1975, she kept working, often harder than colleagues half her age.

"She was the most dedicated person I've ever met, probably in my life," Yale astronomer Richard Larson told the Globe earlier this year. "One way to put it: I think she spent more hours in her office at the age of 80 or 90 than a lot of younger people at the age of 30 or 40."

In recent years, Dr. Hoffleit stopped making the short walk from her New Haven apartment to her office on campus. She hoped to make it to her 100th birthday because she knew her colleagues were planning a party for her at the New Haven Lawn Club. "I think I'll make 100," she said earlier this year. She did. Dr. Hoffleit turned 100 on March 12 and attended her birthday party the next day wearing a crimson dress. She was in good spirits, friends and col-leagues recalled. But soon after she grew sick. "It's hard to believe she became so ill just a few days later," said Yale astronomy professor emeritus Pierre Demarque. "She had cancer, and it spread very rapidly."

Astrophysicist Bohdan Paczynski April 24, 2007, United Press International

U.S. astrophysicist Bohdan Paczynski, renowned for his research into celestial phenomena, has died after a three-

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AAL Astronomy Associates of Lawrence

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

Celestial Mechanic MAY 2007