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Journal of the Amateur Astrono mers Association of New York March 2012 Volume 60 Number 3 ISSN 0146-7662 AAS Conference Focus New Kepler Exoplanet Discoveries
By SANDRA WAYNE
Our spectacular universe has more secrets than we could ever have perceived. The detection of two doubl e-sun planets, or circumbinary planets was just one of the extraordinary topics discussed at the American Astronomical Societ y (AAS) Conference on January 11. The double-sun planets, Kepler-34b and Kepler -35b are Saturn-like in mass and orbit a pair of stars (aka binary stars`). All three bodies (a planet and binary stars) are in motion. While the planet orbits the binary stars, the gravitationally bound pair of stars (binaries) orbit around each other. In presenting his research at the AAS conference, Dr. William Welsh , associate professor of astronomy at San Diego State University stated: It was once believed that the environment around a pair of stars would be too chaotic for a circumbinary planet to form, but now that we have confirmed three such planets. We know that it is possible, if not probable, that there are at least millions in the galaxy. The circumbinary planets were identified using data retrieved from observations conducted on several continents, previous data that had been collect ed several decades ago, and through precise analysis of measurements using the transit detection method. The transit method measures the reduction in a star`s luminosity as a planet passes in front of that star. If the dimming occurs at regular intervals and lasts a fixed length of time, it often means that a planet is transiting` that star. The findings also indicate that Kepler -34b eclipses ever y 4 weeks and that approximately 45% of the light is lost during those eclipses. Kepler-34b orbits two Sun -like stars every 289 da ys, while the two stars in question orbit and eclipse each other ever y 28 days. Both planets are considered as being out of the habitable zone and will more than likely have extreme weather patterns and seasonal changes that are unlike anything scientists can imagine. And so, we wonder, what other remarkable planetary worlds are out there. What new configuration might we come across? For now, we will have to wait....at least until summer, as Kepler`s next data release is scheduled for June, 2012. For more on information on the Kepler mission, see Tony Hoffman's "IN DEPTH" column on Page 4

EYEPIECE
Witnessing The Last Space Shuttle Launch
By AMY WAGNER
Several years ago I made a promise to mys elf: I was going to see a space shuttle launch in my lifetime. After all, what in the world has humankind ever achieved that is greater than the ability to fly off of this world? But last spring I realized I was running out of time ­ the shuttle program was canceled and would come to a close in August. So I planned. For 30 years, NASA`s Space Transportation System gave the world exhilarating triumph, agonizing heartbreak, and enduring hope. For science fiction fans like me, it validated our fascination with the mysteries of the universe and technological possibilities for the future and, for true closure, it gave us an orbiter called Enterprise (Despite naming the first test space shuttle Constitution in 1976, a massive write-in campaign from Star Trek fans persuaded NASA to change its mind). The final launch of Atlantis` mission STS-135 was scheduled for 11:26 a.m., Friday, July 8. Scheduled is the operative word here as there is no guarantee that the launch will occur as planned. Down to the very last seconds of the countdown a launch can be scrubbed, so one has to be prepared for disappointment. Fearlessly, I bought a plane ticket and booked a shuttle tour from Orlando to Cape Canaveral with admission to the Kennedy Space Center and a ticket to view the launch from the Causeway, a strip of land 6.5 miles across from the launch pad ­ the closest position available to the public. Since Columbia`s mission STS-1 launched on April 12, 1981, 355 people from 16 countries have flown 852 times aboard five shuttles, traveled more than 542 million miles, and conducted more than 2,000 scientific experiments. For this final mission, Atlantis would deliver spare parts, equipment, and supplies to the International Space Station, including enough food to sustain station crew through 2012. The day before launch, two lightning strikes hit near the launch pad, one 515 feet from Atlantis. Forecasters predicted stormy weather over the next 24 hours, with only a 30% probability of a go for Frida y`s launch. Sunday would be the final da y in the shuttle's launch window. If weather remained a problem STS-135 would not go up at all. The shuttle program would be over. I tried not to think about that. I was here to witness history. Shuttles aren`t the only cra ft a ffected by bad weather. My 4:30 p.m. flight from LGA is grounded when I arrive to begin my journey. I am going to miss my Atlanta connection and my own personal mission could be scrubbed. This is too important. I cut my losses and purchase a direct flight to Orlando. We have liftoff. Touching down at 1:15 a.m., I reach the tour bus site just
Last Space Shuttle Launch continues on page 5


EYEPIECE

March 2012

WHAT'S UP IN THE SKY
AAA Observer's Guide for March 2012 By RICHARD ROSENBERG

AAA LECTURE SERIES PRESENTS
Lensing Physicist and Planet-Hunting Pioneer By DAN HARRISON
The AAA will have two lectures this month. On Frida y, March 2, Dr. Charles Keeton II, associate professor of physics and astronomy at Rutgers University, and faculty director of the Aresty Research Center, will speak on A Ray of Light in a Sea of Da rk (Matter). On Friday, March 30, Dr. Debra Fischer, Yale professor of astronomy, will discuss Searching for Earthlike Worlds. Lectures begin at 6:15 p.m. in the Kaufmann Theater at AMNH. Keeton tells Eyepiece: In the 1930s, Einstein used his theory of relativity to predict that the bending of light by a star`s gravity could create multiple images of a more distant star. Toda y there are many observed cases where the gravity of a distant galaxy bends the light from an even more distant quasar. This gravitational lensing provides a unique opportunity to study the invisible dark matter thought to surround all galaxies, and even to detect galaxies we cannot see. The search for invisible galaxies with gravitational lensing will provide important clues about the nature of the exotic substance that pervades the universe. After earning a B.A. from Cornell and a Ph.D. from Harvard, Keeton did research at the University of Arizona and the University of Chicago before joining the Rutgers faculty in 2004. He`s observed with the Hubble Space Telescope as well as obs ervatories in Arizona, Hawaii and Chile. Keeton`s research has been featured by National Public Radio, MSNBC.com and New Scientist magazine. In 2010, Keeton received the Presidential Early Career Award for Scientists and Engineers from President Obama. On Searching for Earthlike Worlds, Fischer notes that astronomers have been discovering exoplanets for the past two decades. Most detected exoplanets are fairly massive gas giants, reflecting a bias in discovery techniques. However, the ra ce is on to detect smaller worlds that orbit at distances where liquid water might pool on the surface and provide an environment similar to the one on Earth where life has flourished. I will discuss factors that have lead to a habitable world here and highlight efforts to find planets that remind us of our home world. Fischer began hunting for exoplanets in 1997, measuring tiny periodic shifts in radial velocities of stars. She discovered the first known multiple planet system in 1999 and contributed to the planet formation theory by quantifying the impact of chemical composition on planet formation. From 2003 to 2008, Fischer led an international consortium to carry out a search for planets around metal-rich stars. That project alone detected more than 50 extrasolar planets. Some of these planets transit in front of their stars and the measured decrement in starlight reveals the mass, size and density of the planets. Fischer, who has been at Yale since 2009, is principal investigator for the Cerra Tololo Interamerican Observatory, a highresolution spectrometer, where her team is carrying out a search for rocky planets around our nearest stellar neighbors, the alpha Centauri A and B stars. Fischer`s team is developing nextgeneration instrument designs that aim to break current records and detect Earth analogs that will be targets in the search for life.

March's Evening Planets: This will be a spectacular
month. At dusk spot Venus - brilliant in the west and almost as bright as Jupiter when March begins. Watch as they approach each other, with Venus passing Jupiter on the 13th. For the first 10 days of the month, about a half hour after sunset, Mercury appears below Venus. In the east Mars is already up and at opposition on the 3rd and brightest two da ys later. Finall y Saturn rises about 10 p.m. as March begins, 8 p.m. as it ends.

March's Evening Stars: Orion and his cohorts (Taurus,
Auriga, Gemini, Canis Major and Canis Minor) can still be found in the evening, moving west to make wa y for the spring constellations. The best-known of the spring stars is Leo the Lion with its bright star Regulus (and currently the planet Saturn). BoЖtes, the Herdsman, contains spring`s brightest star Arcturus. A number of open clusters can be seen in binoculars, including the Beehive cluster in Cancer the Crab and a large cluster in Coma Berenices (Berenice`s Hair).

March's Morning Planets: Most of the planets have set,
and we`re left with Mars and Saturn before sunrise. Mars is soon swallowed up by the oncoming dawn, while Saturn is visible a while longer.

March's Morning Stars: The spring stars have moved into
the western part of the sky. Besides Leo and BoЖtes, we can spot Virgo the Virgin. She has a visitor - the planet Saturn. The late spring and early summer constellations can be seen as well. Corona Borealis, Hercules, and especially the Summer Triangle of Lyra, Cygnus and Aquila all fill the night sky.

March Day-by-Day
M M M M M M M M M M M M M M M M M M M arc arc arc arc arc arc arc arc arc arc arc arc arc arc arc arc arc arc arc h h h h h h h h h h h h h h h h h h h 3 5 5 6 7 8 10 11 13 14 20 21 22 23 24 25 26 27 30 Mars is at opposition Mars is closest to Earth Mercury is at greatest elongation from the Sun Moon is to the right of the bright star Regulus The Moon is lower right of Mars Full Moon at 4:39 a.m. (EST) Moon is near Saturn and the bright star Spica Daylight Saving Time begins at 2 a.m. Venus passes near Jupiter in the evening sky Last Quarter Moon at 9:25 p.m. (EDT) Spring begins in the Northern Hemisphere Mercury inferior conjunction with the Sun New Moon at 10:37 p.m. (EDT) A ver y thin crescent Moon rises in the west a half hour after sunset Uranus is in conjunction with the Sun The Moon is near Jupiter tonight Moon is near Venus and the Pleiades tonight Moon to the right of the bright star Aldebaran First Quarter Moon at 3:41 a.m.

Fischer is a University of Iowa graduate, has a master`s of science in physics from San Francisco State University and a doctorate in physics from the University of California.
AAA's final 2011-2012 lecture will be held May 4 when The Astronomical Future of Humankind will be discussed.

For more information go to: www.aaa.org/month1203 2


EYEPIECE

March 2012

A Message from AAA President Richard Rosenberg Hello Members: For nearly six years I have had the honor of being president of the AAA. I will not be running for that posit ion again this year, although I hope to remain on the board of directors. I am able to do so because several members have demonstrated their capabilit ies to beco me excellent presidents. AAA is fortunate to have a focused group of individuals committed to increasing our collect ive experiences in astronomy. During my t ime on the board, I have worked with a number of dedicated club members. Together we have increased our membership and visibilit y, added weekly observing at the High Line and Brooklyn Bridge Park, scheduled mo nthly out -of-town summer observing events, kept our financials in good shape, presented informat ive classes in astronomy, and restored the AAA seminar. Our outreach programs have touched both communit ies and schools. I know that our future is in good hands. As satisfying as the last six years have been, I have been fortunate recently to have a wonderful woman enter my life. In releasing my presidential responsibilit ies, I can dedicate more of my personal t ime to this relat ionship. I do this confidently knowing that the AAA has an abundance of talent to continue to move forward. I do intend to continue my What`s Up in the Sky column in Eyepiece and AAA website page. Sincerely

Rich Rosenberg, AAA President Email: president@aaa.org ; Telephone: (718) 522-5014 A Short Peek: Re-Introducing the Black Hole
In 1971, I was an associate editor of Ph ysics Toda y, the flagship publication of the American Institute of Physi cs. The eminent Princeton astrophysicist John Archibald Wheeler had promised an article on the black hole to be written by him and his Italian collaborator Remo Ruffini, but months had passed...and nothing. So the editor -in-chief fired up his expense account and sent me to Princeton to get the story. Wheeler had promised to let me spend the day with him and he was as good as his word. The article appeared in the January, 1971, issue. It was the cover story: Introducing the Black Hole. The cover art was commissioned from a staff artist at the Hayden Planetarium (my thrifty editor -in-chief paid $500 for a one-time use). The original still hangs somewhere in the Rose Center, portraying a beam of light redshirting as it plunges into a ghostly black hole that resembles a cored apple. Wheeler, a visionary physicist and teacher, helped invent the theory of nuclear fission, gave black holes their name and argued about the nature of reality with peers of his time, Albert Einstein and his mentor, Niels Bohr. His article, ghosted by me, is available on-line at the Physics Toda y homepage. In 41 years much has changed, but much has also stayed the same. If Wheeler was still here (he died in 2008), he'd probabl y sa y "The black hole still has no hair." What he meant by that back in the 1970s was that a black hole is described full y by three numbers: its mass, its angular momentum, and its baryon number. Eyepiece has reached out to Neil deGrasseTyson, director of the Rose Center and David Helfand, professor of astronomy at Columbia for their perspectives on the question: Are black holes still bald? We await their re-

By Dr. David Weinflash
sponses for a follow-up article. The more we learn, the more we realize we have yet to understand. Just ask any string theorist or researcher following Einstein`s Theory of Relativity. Bending space and time? It`s out there for us to grab, but we do not yet have the answers t o m a k e t h e p u z z l e p i e c e s a l l fi t t og e t h e r . While we wait, let`s go back to the basics. Gravity is the weakest force in nature, but because it is attractive and universal, it wins out over the other forces. Gravitation contracts and the forces that resist are, one by one, defeated. Newton knew this. The result is the point mass, the abstraction that you use in orbit calculations, but this time, it's a real point mass. In Newton's theory, the force of gravity becomes infinite at an infinitesimal distance. In Einstein's theory, it's worse: you get the Schwarzschild solution, published in 1915 by astrophysicist Karl Schwarzschild, father of Martin, noted astronomer. This is where the black hole started, but a serious paper wasn't published until 1939 by Oppenheimer and Hartland Snyder. Eyepiece looks forward to additional installments by AAA member and contributing writer, Dr. David Weinflash

Black Holes-- A Long Time/A Brief History
1783 1916 1915 1939 1967 2011 English scientist John Michell hypothesizes concept Einstein's Theory of General Relativity released Schwarzschild solves Einstein's black hole equation Oppenheimer/Snyder Physics Review paper Archibald Wheeler coins the phrase Black Hole Black hole 10 billion times the Sun's size discovered 3


EYEPIECE

March 2012

IN DEPTH: Kepler: NASA's Exoplanet Sleuth
In last month's issue of Eyepiece, I described the HARPS (High Accuracy Radial Velocit y Planet Searcher) project, which has found approximatel y 150 exoplanets (worlds orbiting other stars). This month, it's NASA's Kepler mission's turn to be featured. Along with 61 con rmed exoplanet discoveries, the project has announced 2,326 planet candidates, many of them earth-sized and many within their star's habitable zone. It's alread y made some tantalizing discoveries, and the best are likely yet to come. Kepler is a spaceborne observatory. Launched March, 2009, into a heliocentric orbit, it perpetually examines the same star field. With a 372 -day orbit, the spacecraft is slowl y receding from the Earth. Its telescop e's mirror is 1.4 meters in diameter, and its sensors have a resolution of 95 megapixels. This is serious observing equipment. While HARPS uses spectroscop y to search for small changes in a star's velocit y caused b y the tug of an unseen planet, Kepler searches for minuscule dips in a star's brightness as a planet transits (passes across) the star's dis--a k phenomenon we'll b e treated to in our own celestial backyard on June 5 when Venus transits the Sun. Kepler uses a very sensitive photometer to monitor a star field containing 156,000 visible stars in Cygnus and Lyra. Ever y 29 minutes it takes an image of the field, recording precise brightness measurements for each of them. Kepler has compiled light curves--graphs for each star showing fluctuations in its brightness over time. Utilizing computer programs to search for periodic brightness indicative of planetar y transits, it has found them in abundance. Other phenomena can mimic transits: stellar variability; an eclipsing binary system in which a pair of stars eclipses each other in turn; and "contamination" of a star's light

By Tony Hoffman
curve b y a nearb y eclipsing binary. Although the vast majority of Kepler's candidate worlds are likel y to be planets, the y require final confirmation b y other methods. Although only a small p ercentage of Kepler's candidates have yet b een confirmed, the pace is increasing. On January 26, NASA announced Kepler's largest batch of planet con rmations yet, a trove of 11 multi-planet systems containing 26 worlds, plus several additional prospective planets. Kepler counts some intriguing discoveries among its growing list of discoveries. In Septemb er, NASA announced the discover y of Kepler-16b, a world that bears a superficial resemblance to the Star Wars home world of Luke Skywalker, Tatooine, as it orbits a nearb y double sun. Such circumbinar y planets are not uncommon, as Kepler has since announced two more of them. The hol y grail of exoplanetolog y is finding an earth sized planet orbiting a sun-like star in the aptly named habitable zone (aka the "Goldilocks zone") for b eing neither too hot nor too cold, but just right for water to exist in liquid form. Kepler-22b, announced on Decemb er 5, is a "supe-r Earth" 2.4 times the radius of Earth, and orbits a G-typ e star a little smaller and cooler than our Sun, every 290 days. If the planet has a greenhouse e ect similar to Earth's, it would have a surface temp erature of about 72 degrees. Scientists have no knowledge of the planet's atmosphere or comp osition yet, so it's premature to term it "earthlike", but a compelling find nonetheless. Another Kepler find, the Kepler-20 system, contains five planets, two of which are Earth-sized, though neither are in the habitable zone (they orbit their star in only 6.1 and 19.6 days, respectively). Even non-professionals are finding worlds in Kepler data. Citizen scientists in the Planet Hunters project scour Kepler light curves online for transits. If enough hunters find something suspicious in a light curve, the project's science team looks closer. Four promising Planet Hunters discoveries, missed b y the full-time Kepler team, have been written up in scientific papers, listing the volunteers as co -authors. These worlds await final confirmation. There are a numb er of other prospective planets flagged b y volunteers that have yet to be announced. It's a wonderful chance for the pub lic to get involved in cutting-edge scientific research. Kepler, which costs $18 million to op erate, is up for re funding this year as its 3-year mission concludes. NASA is under intense budget pressure, and there is no guarantee that Kepler will survive, but if there ever was a mission worthy of support based on its results to date and future potential, this is it. The longer Kepler can monitor its patch of sky, the more planets it will be able to detect and confirm, especiall y ones with longer-p eriod orbits (of Earth-length or longer), as you need at least 3 transits to confirm a planet. Kepler is already revolutionizing our understanding of the diversity of planetar y s ystems. Let's not leave Kepler's work mostly undone.

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Last Space Shuttle Launch continued from page 1

March 2012

in time to pick up my tickets. Since its inception, the shuttle program has faced criticisms and setbacks. Catastrophe struck twice, with disasters claiming the lives of 14 astronauts. In 1986, Challenger exploded 73 seconds after liftoff as we all watched in horror. In 2003 Columbia disintegrated in the atmosphere upon reentry, the white trails of smoke and wreckage silently crossing the bright blue sky, all of it permanently etched in our minds. The shuttle program also struggled with budget, costing $200 billion with an average cost of about $1.5 billion per flight over the life of the program. At 4:00 a.m. our bus pulls into Kennedy Space Center. Thousands of people are waiting to share in this historic event. But it will be hours before busing to the Causeway, so I have time to grab a bite and explore the grounds. Fortunate for me, it`s the Summer of Sci-Fi ­ a presentation devoted to Star Trek. With luggage in tow, I check out memorabilia and visit a replica of the Enterprise`s bridge (well, of course I sit in the Captain`s chair). We are called to queue up to exit. Three hours later we are on our way to our viewing site. Despite its astronomical price and human cost, the shuttle program has made invaluable contributions to our understanding of the universe and how we live in space. The single most important contribution has been the delivery, repair, and maintenance of Hubble, which has extended our reach into the cosmos and back in time. Spacelab missions in biology and physiology have established the effects of microgravity on the human body. Additionally, items first invented for applications on the space shuttle are now widely a vailable for commercial use, including LED lights, carbon monoxide detectors, and sensors for harmful chemicals used in industry and manufacturing. We arrive to the Causeway about 2 Ѕ hours before launch time; plenty of time left to find a spot and buy some souvenirs. The crew of Atlantis ­ Commander Chris Ferguson, Pilot Doug Hurley, Mission Specialists Sandra Magnus and Rex Walheim board the orbiter. Speakers begin pla ying the broadcast from Launch Control at the Kennedy Space Center, with longtime NASA announcer George Diller narrating the dialogue between the launch team and the Atlantis crew. Over the past 24 hours, Go/No Go polls have been taken, and the final poll is completed at T minus 9 minutes: all are go for launch. NASA Shuttle Launch Director Mike Leinbach calls Commander Ferguson: And Fergie, for the final time...Good luck to you and your crew on the final flight of this true American icon. Good luck, Godspeed, and have a little fun up there. Commander Ferguson replies, "Thanks to you and your team Mike, we're completing a chapter of a journey that will never end. The crew of Atlantis is ready to launch." The spectators on the Causeway erupt in cheers. The shuttle program has proven that reusable space vehicles are possible, that people from different nations can explore space in a new era of cooperation, that humans can adapt to microgravity to live and work in space, that we can study the Ea rth as a single, complex s ystem from low-orbit, and that there is no glass ceiling in space ­ women can be astronauts. Elation ­ my series of misadventures are about to pa y off. But like all good storytellers, NASA has a gift for building tension toward the climax. At T minus 31 seconds, just before Atlantis's computers will take control of the flight, we hear the launch team request a hold; the countdown clock stops and Diller announces, We have a failure. The launch team cannot get an indication that the Gase-

ous Oxygen Vent Arm has retracted and properly latched. I can see it from here, says the guy next to me, looking through the high-powered lens of his camera. Just look out your window! shouts someone else in the crowd. We all laugh, but mostly out of nerves. With a window of only 10 minutes, they must find a solution or else the launch will be scrubbed. The launch team positions a closed circuit camera to verify that the GOV arm has separated, and after the longest 3 minutes and 16 seconds of our lives, we hear a series of voices announce, I concur, and the clock is reset, the countdown resumes, and control is given to the Atlantis crew for liftoff. "Two, one, zero and liftoff! The final liftoff of Atlantis ­ on the shoulders of the space shuttle, America will continue the dream," Diller signs off and the final flight of Space Shuttle Atlantis has lifted off on Frida y, July 8, 2011 at 11:29:03.9 AM EDT to the cheers of nearly one million people in and around the Kennedy Space Center. The ground rumbles and roars. Seven seconds later, we hear the excited voice of Commander Ferguson: Houston, roll program! and the exuberant response from Houston: Roger roll, Atlantis! (The roll program rotates and tilts the vehicle to align it in the proper direction to meet up with the space station). Mission Control Center at the Johnson Space Center in Houston now has control for the duration of the 13-da y mission. A new narrator tells us, The space shuttle spreads its wings one final time for the start of a sentimental journey into history. And that`s exactly what it is now: history. Dismantling the shuttle program has left huge questions about the future of NASA and manned spaceflight. In 2010, President Obama canceled the planned Constellation program that would launch the next generation of spacecra ft, revealing instead a new plan to promote a commercial manned spaceflight initiative. Tears stream down my face. My own long journey and lack of sleep have surely contributed to my emotional state, but it`s hard to express feelings at the time. The crowd on the Causeway cheers, U-S-A, U-S-A! and while I`m filled with pride in America`s accomplishments and leadership in space, I know this achievement goes beyond nationality. To me, the shuttle program was the pinnacle of human endeavor. The shuttle exemplified our human desire to understand and explore the possibilities of the universe, the will to challenge our own abilities and intellect, and the acceptance of responsibility as caretakers of our planet. As a sci-fi geek, I am wired to believe a new era in space must be on the horizon. Now, if I could only scrape together $200K for Sir Richard Branson, so I can grab a seat next to Stephen Hawking on the next Virgin Galactic flight. Well...it`s good to have goals.

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March 2012

WHAT IF?

By Richard Brounstein NASA'S $100 BILLION BUDGET
nologies to move an asteroid a few thousand kilometers...just enough to miss the Earth. Repeated missions would harness resources from these objects. Imagine the rich minerals and other resources t hat could be returned to Earth or transported to an established space colon y. Mining in space will be essential to our long term survival. It begins with a single mission. Read Buzz Aldrin`s Unified Space Vision for a comprehensive look at what could be accomplished. Engineering economically safer wa ys t o and from Earth orbit is another mission critical goal. Let`s face it; the hardest and most dangerous element in manned missions is liftoff and re-entry. We must develop m ore reliable and flexible spacecraft. Once travel to and from Earth orbit is as convenient as fl ying across the ocean, private industry will invest heavily in space technologies. This is happening on a limited basis today, but not at a pace required to accelerate our reach to nearby planets and other celestial bodies. Mining lunar resources would eventually become profitable, so that a Moon base would not be something politicians just talk about but would be a productive business venture to benefit all. Another goal would be t o finally find those extra terrestrial life forms that almost certainly exist in our solar system. NASA could fund missions to probe the oceans of Europa around Jupiter and the geyser`s on Saturn`s moon, Enceladus. Follow the water and we will hopefull y find life forms. Studying new life forms would provide a unique perspective on how life ma y be forming across the universe. And let`s not forget to send a few probes to Titan to study this moon`s lakes and oceans. It looks so much like Earth, except that it is just a few hundred degrees colder. Most importantly, a $100 billion NASA budget has a hidden benefit for the United States. In order to achieve these loft y exploration goals, NASA would need to invest in our country`s education, retaining a new generation of scientists, engineers and technicians. Once our government increases investment in science-related education, individuals will create innovative solutions and develop private enterprises to execute those solutions. That`s exactly what occurred in the United States from the 1970s to the 1990s. Energy innovations, food production and countless other problems can be solved profitabl y when you have motivated and educated minds. So here we are today, with the government cutting NASA`s budget and removing science education and planetary exploration, two key elements that will contribute to the benefit of our country and our future. But think what we could achieve if money were not an issue. Can we all imagine such a world? ________________________ Richard Brounstein is a monthly contributor to Eyepiece, exploring what today seems improbable or impossible. Stay tuned for more fascinating concepts in "WHAT IF."

In February, the White House proposed NASA`s 2013 budget of $17.7 billion, $59 million below 2012`s budget and $707 million below 2011`s allocation. We are going in the wrong direction. You can check the Web for specific details, but allow me to summarize. Science education and planetary exploration are taking a hit, but most missions will continue at various funding levels. In this month`s What If, we explore the impact of dramatically increasing NASA`s budget instead of allowing it to continue its downward spiral. What does space exploration do for societ y anywa y, you ask? As AAA members, you are probabl y avid supporters of astronomy and space exploration. Unfortunately, we are all in the minority. Exploring the universe with a giant ground based or space-based telescope, sending astronauts back to the Moon or launching probes to Mars and Pluto may stir your passion for exploration and knowledge, but talk to the masses out there ­ as a group, they aren`t very excited at all. But the y should be. If nations had not explored outer space over the past 50 years, we would be living in a ver y different world. This is not an exaggeration. My favorite example is the integrated microchip. Invented in 1958, the same year that NASA was created, this new technology was expensive and underutilized. However, NASA`s Gemini and Apollo programs found the technology essential to successful space missions. Spacecraft could not maneuver without a small, low-power, lightweight guidance system computer performing thousands of computations per second. So NASA invested millions of dollars into perfecting the technology. Microchips would have taken many more years to make their wa y into the core of our societ y`s technological development without direct government participation. After Apollo, integrated microchips changed our world in wa ys that no one could have imagined. Private industry adapted to invent new applications. From science to business to entertainment, this one key discover y reshaped our lives on the planet. Make a phone call, send an email, trade a stock, turn on your Go To Scope, or consult your car`s GPS. We have NASA`s foresight and involvement to thank for all of these advances. The microchip is just one of the many benefits humankind has derived from NASA`s pursuit of space travel. Now imagine what could happen if NASA approached space travel today the wa y they approached it in the 1960s. If NASA`s yearly budget was $100 billion (a small fraction of what the United States spends on defense, by the wa y), what could they accomplish? One high budget goal is to initiate manned exploration of asteroids and comets. Sending probes is not enough. We must develop wa ys t o influence these objects in space. Somebody's got t o make the decision to actually mount the deflection and do it," said Apollo 9 astronaut Rust y Schweickart, chairman of the B612 Foundation , a group dedicated to predicting and preventing catastrophic asteroid impacts on Earth. With proper funding NASA could create tech6


EYEPIECE

March 2012

AAA BRIEFS IN ASTRONOMY TO LIFE, TO LIFE
A potentially habitable alien planet, GJ 667Cc, the best candidate yet t o harbor water, and possibl y even life, on its surface--has been found around a nearby star. The planet is in the habitable zone of its host star, a narrow circumstellar region where temperatures are neither too hot nor too cold, so liquid water could exist on the planet`s surface. Researchers estimate the planet is at least 4.5 times as massive as Earth, making it a super-Earth. It takes 28 days t o orbit its parent star in Scorpius, a mere 22 light-years from Earth. The host star, GJ 667C, a member of a triple-star system, is an M-class dwarf star about a third of our Sun`s mass. While faint, it can be seen by ground-based telescopes. The discovery of a planet came as a surprise, because the star system has a much lower abundances of heavy elements. The discover y could mean potentially habitable worlds in a greater variety of environments than thought possibl e. Another super -Earth orbiting much closer to GJ 667C was detected in 2010, but never published. This planet, GJ 667Cb, takes 7.2 days t o circle the star but its location makes it far too hot to sustain liquid water on its surface.

EVERYTHING MATTERS
Exosol ar matter has bee n detected for the first time by a NASA spa cecra ft has from outside our solar syst em, el sewh ere in the galaxy. The material wa s spott ed by a spa cecraft studying the edge of the solar syst em fr om its orbit a bout 200,000 miles a bove Earth. Findings included first det ecti on of ali en particles of h ydrogen, ox ygen and neon, in addition to con firmation of previ ousl y detect ed helium. These at oms are remnants of ol der stars that ended their lives in supernova s, which dispersed the elem ents throughout the galaxy. As interstellar wind bl ows these charged and neutral particles through the Milky Wa y, the probe creat es a census of el ements present. Researchers found 74 oxygen atoms for ever y 20 neon atom s in the interstellar wind. For com parison, there are 111 oxygen at oms for ever y 20 neon atoms in our sol ar syst em. The presence of less ox ygen within interstellar material could indicate the Sun form ed in a region with less oxygen compared t o its current locati on. The interstellar wind travels sl ower and from a di fferent directi on than thought. Research now shows the interstellar wind exerts 20% l ess pressure on the heliosph ere, a protecti ve bubbl e shielding our solar system from cosmic ra ys.

THE BEST AND THE BRIGHTEST
Massive solar flares have erupted from the Sun in recent weeks. One on January 27, the strongest to that point this year, was rated an X1.7-class eruption, the most powerful t ype of solar storm. The flare unleashed a coronal mass ejection, but fortunately wasn`t pointed at Earth. The flare exploded from a particularly active sunspot region. Days earlier, a separate blast from the same region sent a cloud of charged particles toward Earth and sparked the strongest radiation storm since 2003. These and other flares have produced flamboyant auroral displays. The Sun`s activity ebbs and flows in an 11 -year cycle. It`s in the midst of Solar Cycle 24, with activity expected to ramp up toward solar maximum in 2013. Meanwhile, NASA reports that while these st orms have the potential to damage satellites and power infrastructures, they can also clear the skies of dangerous space debris. Energy from these coronal mass ejections causes the atmosphere to expand, creating more friction on pieces of orbiting space junk. The resulting drag sends debris plummeting back toward Earth faster than trash from previous years. In another piece of news, a January 22 solar eruption was so strong that it was felt by NASA`s Marsbound Curiosity rover.

LIKE LOOKING IN A MIRROR
An uncanny twin of the Milky Way takes center stage in a new Hubbl e pi cture. The phot o shows galaxy NGC 1073, a barred spiral 55 million light -years a wa y in Cetus. By l ooking at phenomena beli eved similar to our galactic home, astronom ers hope to learn more about the Milky Wa y, which we can onl y see fr om the inside. The bars, made of dense lines of stars at the galaxy`s center, are thought to form as gravit y ca uses densit y wa ves that push gas in ward, suppl yi ng material for new stars. This inflow of ga s can also feed hungr y giant black hol es th ought to inhabit the centers of m ost such galaxies. Sci entists think spiral galaxies` central bars might form as they a ge, in part because galaxi es dating fr om the universe`s earl y da ys t end not to have them. About on efi fth of spiral galaxies from the earl y universe contained ba rs, while m ore than two-thirds of spirals seen toda y have them.

SEARCH WITH THE HOLY GRAIL
A NASA Grail pr obe gravity-mappi ng spacecraft or biting the Moon has beam ed h om e video footage of the far si de. The video wa s captured by one of the t wo spa cecraft t hat have been circling the Moon since arriving over the Ne w Year. The video sh ows the far side a s a stark, scarred landsca pe, with doz ens of craters visi bl e.

TWINKLE, TWINKLE, LITTLE...NOT
Stars viewed by an observatory in Chile have just lost their twinkle. Images from this ground-based telescope are brighter and clearer than ever before, thanks to a new instrument on the Gemini South observatory that reduces the blurring, or twinkle, caused by Earth`s atmosphere. By relying on a combination of light-wave sensors and adaptive optics, astronomers can subtract out the turbulence, improving images. A recent upgrade to Gemini South takes this to a new level. Its new photos are Hubble quality, a significant step for an telescope on Earth. Adaptive optics from the ground is several orders of magnitude cheaper than sending telescopes into space.

NO THIRST ON VESTA
The giant aster oid Ve sta may c ontai n a vast supply of water ice, a suppl y that has sat frozen for billi ons of years, a new stud y reveals. Water ice ma y lurk underground over roughl y half of Vesta`s area, particularl y near the poles. Water ice is thought abl e to survi ve in the top 10 feet of soil.
Briefs in Astronomy continue on page 8

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I'LL FOLLOW THE SUN (SPOTS)
Scientists may be closer to unraveling the mystery of sunspots, thought to occur when increased magnetic activity inhibits the flow of heat onto a patch of the Sun, causing it to darken. The ultimate source of that magnetism is unclear. Researchers say formation of hydrogen molecules may decrease pressure on certain areas of the Sun`s surface, allowing runawa y magnetic fields to form and intensify. Because the Sun is so hot, this hydrogen is generally in the form of single ionized atoms--only the hydrogen nucleus--floating around in gaseous form. However, inside sunspots the surface of the Sun can cool enough to allow t wo h ydrogen atoms to bond to form hydrogen molecules. When two atoms combine into one molecule, the pressure it exerts is about half the pressure of the two particles it used to be. And when pressure decreases, magnetic fields can further intensify. While scientists cannot directl y observe hydrogen molecules on the Sun, they searched for a stand-in, the molecule hydroxyl, which contains one hydrogen atom and one oxygen atom. Because this molecule breaks up at a lower temperature than molecular hydrogen, the team knew that where hydroxyl is found, hydrogen molecules can also exist.

SPITZER SPIES AN EXOPLANET
Observations of an alien planet orbiting close t o its star suggest the rocky world might not be a scorching hot wasteland. Super-dense 55 Cancri e, 40 light-years from Earth, takes 18 hours to orbit, 26 times closer to its star than Mercury is to the Sun. Because of its tight orbit, 55 Cancri e was thought to harbor surface temperatures as high as 4,800 degrees. But new Spitzer observations have astronomers revisiting the exoplanet, armed with clues that it may be wetter and weirder than thought. Researchers measured the faint dip in brightness caused by 55 Cancri e passing in front of its star. Since these transits occur ever y 18 hours, scientists have many opportunities to collect enough data to help them estimate the size, volume and density of the planet. Based on these results, researchers calculated its mass at 7.8 times Earth`s and a width just over twice ours. These data place 55 Cancri e in the super Earth class of exoplanets. Original size and mass estimates indicated it was an ultra-dense rocky world, but new observations suggest a fifth its mass is light elements and compounds, including water. Given 55 Cancri e`s extreme temperatures and high pressure, these elements and compounds likely exist in what`s a supercritical fluid state, best imagined as liquid like gases in high pressure and temperatures.

EVERYONE INTO THE WATER ­ ON MARS
An ESA spacecraft orbiting Mars has found more evidence an ocean may have covered parts of the planet billions of years ago. Mars Express detected sediments on Mars` northern plains reminiscent of an ocean floor, in a region that was earlier identified as the site of ancient Martian shorelines. Mars Express uses a radar instrument, MARSIS, to probe beneath the surface and search for liquid and solid water in upper portions of the crust. Researchers analyzed more than two years of MARSIS data and found the northern plains are covered in low-density material that suggests the region may have been an ancient ocean. MARSIS penetrates deep into the ground, revealing the first 60-80 meters of the planet`s subsurface. Throughout this depth, there`s evidence for sedimentary material and ice. The ocean would have only been a temporary feature. The water would likely have been frozen or preserved underground again, or turned into vapor and lifted graduall y into the atmosphere within a million years or less.

FROM RUSSIA WITH LOVE
Cosmic radiation most likely caused the demise of a Russian Mars probe that got stuck in Earth orbit shortly after its Novem ber launch and crashed back to the surface in early January, the chief of Russia`s space agency said. Although an investigation pointed to cosmic radiation as the likely culprit in failure of the Phobos-Grunt mission, an imported spacecraft component may not have been adequately hardened for space`s harsh radiation environment. After being marooned in Earth orbit for more than two months, Phobos-Grunt fell back to Earth and plunged through the atmosphere January 15, reportedly breaking apart over the Pacific Ocean off Chile.

ALL GROWN UP
Clusters of distant galaxies bursting with newborn stars in the early universe eventually became the most massive galaxies today. Star formation was abruptly cut short. Researchers point to the eating habits of supermassive black holes. For the first time, scientists show a clear link between the most energetic starbursting galaxies in the early universe and the most massive galaxies today. Astronomers found closel y grouped galaxies have larger halos of dark matter. To study how the y evol ved, researchers measured masses of dark-matter halos around galaxies and used computer simulations to predict growth over time. Calculations showed they become giant elliptical galaxies, the most massive in the universe. While some underwent a frenzy of intense star formation, the phase lasted only 100 million years. What caused this abrupt end to rapid star formation is mysterious. Intense bursts of star formation could have powered quasars. Quasars are powered by supermassive black holes at their centers, and as they flung powerful bursts of energy into the cosmos, they also could have blown awa y galaxies` surrounding gas, the raw material from which stars are born. This dynamic process could have been powerful enough to abruptly shut down rapid star formation.
Briefs in Astronomy continue on page 9 ries continued on p

UPS AND DOWNS ON TITAN
Titan's huge sand dunes vary according to elevation and latitude, providing clues about the moon`s climatic and geological history, a recent study reported. Dunes are bigger and thicker in southern latitudes, and at relativel y lower altitudes. Dune fields are restricted to equatorial regions, from roughl y 30 degrees south to 30 degrees north. They`re bigger than Earth`s, on average 0.6 to 1.2 miles wide, hundreds of miles long and about 300 feet high.

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Mars' surface may have been parched too long for any life forms to exist, a new study suggests. Researchers spent three years examining particles of soil collected in 2008. According to their observations, the surface may have been arid and desolate for more than 600 million years, despite the presence of ice and despite previous studies that indicate the planet ma y have experienced a warmer and wetter past more than 3 billion years ago. This could mean the surface has been too hostile to support life. Even though there's an abundance of ice, Mars has been experiencing a super drought that may have lasted hundreds of millions of years. Scientists think the Mars we know toda y contrasts sharply with its earlier history, which had warmer and wetter periods and which may have been more suited to life. Researchers found the soil had been exposed t o liquid water for no more than 5,000 years since Mars formed billions of years ago. If this is the case, the water was likely on the surface for too short a time. Researchers looked for clay particles formed when rock is broken down by water. If present, clay signals an interaction between soil and liquid water. But the team found no signs of this crucial marker. Still, the findings are not necessarily a nail in the coffin of Martian life. Such life may still be taking refuge underground. A dwarf galaxy, invisible to telescopes and possibl y completely composed of dark matter, has been discovered by astronomers. The galaxy orbits a larger galaxy. Scientists detected its presence through tiny distortions its gravity causes to passing light. Discovering dark objects like this galaxy could help researchers better understand dark matter and how it affects regular matter around it. The dwarf galaxy, seven billion light-years away, weighs about 190 million times the mass of the Sun. It's the lowest-mass galaxy ever seen at this distance. Farther away, at about 10 billion light -years, is another galaxy whose light passes the dwarf and its host en route to Earth. As this light travels through space, it's bent by the gravity of the intervening galaxy and its satellite, causing gravitational lensing. Although most of this warping is caused by the larger gravitational tug of the host galaxy, a computer model detected a slight excess of warping caused by the tiny addition of the dwarf galaxy's gravity. It's uncertain if the galaxy is made almost exclusivel y of dark matter, or if it just contains stars too dim to be visible at this distance.

THE DEEP MEANING OF LIFE

THE BRIGHTEST AND THE BEST

The brightest galaxy ever seen through a cosmic "zoom lens," a fluke of astrophysics, has been revealed by scientists. The galaxy, 10 billion light-years from Earth, was spotted by Hubble using a gravitational lens created by a massive cluster of cl oser galaxies about 5 billion light -years awa y. The distant galaxy is three times brighter than anything seen through a gravity lens. The observation provides a unique opportunity to study physical properties of a galaxy vigorousl y forming stars when the universe was only one-third its present age. Astronomers aimed Hubble at cluster RCS2 032727-132623, surrounded by a nearly 90-degree arc of bright light from an even more distant galaxy. Because of gravity distortions, the image of the background galaxy is repeated several times, a feature of gravitational lenses. Astronomers used data from Hubbl e's observations to remove distortions caused by the gravitational lens, revealing a view of the distant galaxy filled with star forming areas that shine brighter than similar spots in the Milky Wa y. Titan may be more similar to an Earth-like world than thought, possessing a layered atmosphere. Saturn's largest moon is the only m oon known to have a dense atmosphere. However, there are conflicting details about how it's structured. While Voyager 1 data suggested Titan's boundary la yer was about two miles thick, Huygens saw it as only about 1,000 feet. To help solve these mysteries, scientists developed a climate model of how Titan might respond to solar heat over time. Simulations revealed Titan's lower atmosphere appears separated into two la yers, both distinct from the upper atmosphere in temperature. The lowermost boundary la yer is onl y about 2,600 feet deep and, like Earth's, changes daily. The layer above, 1.2 miles deep, changes seasonally. This work help explains the winds on Titan measured by Huygens, as well as spacing between giant dunes on Titan's equator. It could imply formation of boundary-la yer clouds of methane. A hail of meteorites fell in the Moroccan desert in July and was recovered a few months later. Scientists confirmed in January the rocks are Martian, presumably blasted off the planet by an asteroid strike. Such pieces of Mars have been found on four other occasions, the last in 1962. Just 220 pounds of Mars rocks are known to exist here. The newfound meteorites represent a big chunk of this material, at least 24 pounds. Researchers can glean much information from a small piece of the planet, including about Mars' atmosphere and climate, and its potential to host life. Researchers don't yet know how old the samples are and when they were blasted off Mars. Contacting AAA Website - www.aaa.org

FUNNY, YOU DON'T LOOK LIKE EARTH

DWARFS' MATTER

IT'S RAINING MARS

FOLLOW THE GAMMA-RAY ROAD

Astronomers have discovered a rare binary-star system by following its powerful gamma-ray signal, a find that may remove the element of luck from locating more of its kind. A direct search for gamma rays revealed the system about 15,000 light-years away. The handful of gamma-ray binaries that have been discovered were found serendipitously. But with the newl y found system, astronomers started off with a gamma-ra y source. This system is thought to be a pulsating type of neutron star, interacting with the stellar wind of its companion. Astronomers believe systems containing a quickspinning pulsar eventually become relativel y sl ow-spinning X-ray binaries, which are far more plentiful.

General Club Matters and Observing : president@aaa.org; Membership Business: members@aaa.org; Classes: classes@aaa.org; Seminars: seminar@aaa.org; Eyepiece: editor@aaa.org Telephone (voicemail): 212-535-2922

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FOCUS ON THE UNIVERSE Night Sky Photography
By STAN HONDA
Tripods are essential for good night photography. Since almost all the night sky photographs you will take will be long exposures of up to a minute or even longer, you will need a sturdy tripod to anchor the camera and produce sharp images. For my main tripod I use a Manfrotto 190X Pro B with a Manfrotto 410 head, which is basically an alt-azimuth mount. The tripod has a built-in level, and the head will allow you to adjust the camera in small increments. A standard tripod head that has adjustments for the three axes will do just as well. Even a medium or small tripod will work. For a second tripod I use a small Silk tripod. It`s 14.5 inches long folded and light weight. It is very low to the ground, so often I take a beach towel to lie on as I position the camera. (I do this with both tripods since low angles are best to get foreground objects in the photo.) Try not to extend the legs all the way out so the camera sits high on the tripod legs. You probabl y don`t need the camera to be that high, and the full extension allows the camera to swa y slightly. When only one section of the legs is extended and the camera is low t o the ground, it will be more stable. Better yet, if the tripod legs can be spread out wide from the center column, you will create a low, stable platform for the camera. If you place a camera bag or ankle weights on one or two of the legs, this will anchor the tripod. If there is enough space under the tripod, you can tie weights or a camera bag to the center column, which will pull down and steady the tripod. Another important problem at night is keeping the horizon level. Since it is dark ­ hopefully ver y dark ­ when you are setting up the camera, it can be difficult to compose through the viewfinder. There may be times when you return to your computer and see a tilted horizon in the photos when you don`t want one. It is often best to level the tripod and the camera so the horizon remains straight. There are many twoand three-axes bubble levels that will fit into the camera flash shoe. You can then level the camera after placing the tripod on the ground. After that, you can move the camera horizontall y left to right or up and down and know that the horizon will be straight. For the long exposures an intervalometer is essential. Many digital cameras will take photos as long as 30 seconds, but you`ll need one to three-minute exposures. An intervalometer will plug into something called a remote terminal on the camera, usually near the flash synch terminal. The intervalometer will allow you t o set the exposure time, the interval between exposures, and the number of exposures the camera will take. You can use a remote release that fires the camera or lets you lock the shutter open when the camera is set on the bulb 10

setting, but then you will have to time the exposure with a watch, something which is not recommended, especially i f it is cold. An intervalometer will allow you to take 1-minute exposures of wide areas of the sky, including the Milky Way, and even longer exposures that will result in photographs of star trails. Next month we`ll head out and take some photos.

NYC Shoot : Moon-Venus by Stan Ho nda (Copyright 2011)

________________________ Stan Honda is an accomplished professional photographer and contributing writer for Eyepiece. In this continuing series of articles, he will share his extensive knowledge of photographic equipment and technique. Visit www.stanhonda.com for a complete overview of his work. WHEN YOU GET CAUGHT BETWEEN THE MOON AND NEW YORK CITY An asteroid the size of a cit y bus zoomed between Earth and the Moon`s orbit January 27, just days after its discover y, but it never posed a threat. Asteroid 2012 BX34 passed within 36,750 miles of Earth at its closest approach. The rock is about 37 feet wide and would have broken apart in Earth`s atmosphere long before it reached the ground, if it had reached the planet at all. The asteroid passed Earth at a distance only about 0.17 times that between the Earth and the Moon. On January 23, another small asteroid, 2012 BS1, passed by at a range of about 745,000 miles.


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AAA Events on the Horizon March 2012
Friday, March 2, 6:15 p.m., P
Dr. Charles Keeton, A Ray of Light in a Sea of Dark (Matter) Kaufman Auditorium - American Museum of Natural History Next date: March 30

DR. GLENNYS FARRAR EXPLAINS TIDAL DISRUPTION EVENTS Feb 10 AAA LECTURE REVIEW
By BENJAMIN BURDICK AND ADRIAN VATCHINSKY

Monday, March 5, 7:30 p.m., P
John F. Kennedy and the Race to the Moon with John Logsdon Hayden Planetarium Space Theater

Tuesday, March 13, 6:30 p.m., P
Beyond Planet Earth with Michael Shara American Museum of Natural History - Enter at 77th Street

Tuesday, March 20, 7:30 p.m., P
2012 Isaac Asimov Me moria l Debate: Faster Than the Speed o f Lig ht

Lefrak Theater (Sold Out) ­ American Museum of Natural History Linder Theater (Simulcast Available at Press Time)

Saturday, March 24, 7:30 p.m. -11:00 p. m., P,C
Observing at Great Kills Gateway National Park, Staten Island, P, T, C Next date: April 21

Friday, March 30, 6:15 p.m., P
AAA Kauf Final Futur Lecture ­Debra Fischer, Searching for Earthlike Worlds man Auditorium--American Museum of Natural History Date: May 4: Alex Wolszczan, Penn State, The Astronomical e of Humankind

Friday, March 30, 7:30 p.m. -11:00 p. m., P, T, C
Observing at Floyd Bennett Field, Brooklyn Next date: April 27

Saturday, March 31, 10 a.m. - 12:00 p.m., P,T,C
Solar observing in Central Park At the Conservatory Water. Next date: April 28

Saturday Evenings in March: 7 p.m. - 12:00 a.m., P,C
Stargazing at The Custer Institute 1115 Main Bayview Road, Southold, New York (Call 631-765-2626 to confirm observing conditions)
Legend for Events M: Members P: Ope n to t he public T: Bring your telescopes, binoculars, etc. C: Cancelled if cloudy

For more information, go to: www.aaa.org

NEBULA OF THE MONTH -- HELIX
Looking like a golden eye in the cosmos, the Helix Nebula was recently photographed by ESO`s Vista Telescope, revealing in stunning infrared detail strands of cold nebular gas and a vibrant background of stars and galaxies. Lying about 700 light-yea rs from Earth in the constellation Aquarius, Helix is a planetar y nebula, formed when a star, like our Sun, exhausted its hydrogen fuel. The star`s outer layers expanded and cooled, creating a huge envelope of dust and gas. Radiation flowing from the dying star ionized this envelope, causing it to glow. The term planetar y nebula refers to a superficial resemblance to giant planets when observed through early telescopes.

What is your favorite nebula?
Write eyepieceeditor@g ma il.co m to have yo ur ans wer publis hed!

A recent observational discovery of two tidal disruption events (TDEs), some of the most powerful objects in the universe, was the focus of NYU professor Glennys Farrar during her Feb. 10 presentation at the AMNH Kaufmann Auditorium. Her topic, At Last: Seeing Supermassive Black Holes Shred Stars, explored a personal journey toward identifying a methodol ogy to detect these unique stellar disruptions. A black hole, like any other massive object, has a gravitational field that modulates its strength in proportion to its distance. This creates a tidal force on objects orbiting the black hole. A familiar example is the force of the Moon on the Earth. On the side of the Earth near the Moon, the Moon`s gravity is stronger than at the center, so the water on Earth`s surface is pulled closer to the Moon, causing a high tide. On the far side, the Moon`s gravity is weaker, and so the water is flung outward from the center, creating another high tide. The overall effect is to stretch the water -surface of the Earth into an oblong shape. The effect near a black hole is qualitatively the same, only much more dramatic. A TDE occurs when a star orbiting a supermassive black hole at the center of a galaxy is stretched so much that it actually is ripped apart. If the star is too close, it will get pulled into the black hole. The ideal position is a few times the Schwarzchild radius (just above the surface of the black hole). The star is shredded on a timescale of weeks to months - a blink of the cosm ological eye. Eventually, it is consumed by the black hole, but not before releasing a monumental amount of energy. Farrar first became interested in TDEs during her research on ultra-high-energy cosmic rays (UHECRs.) These particles carry a significant amount of energy, millions of times greater than is achievable in the largest particle accelerators. It is still unknown what process in the universe is powerful enough to accelerate anything to these velocities. Active galactic nuclei (such as those powering quasars), except for the ver y most luminous, are thought too weak to produce UHECRs. Gamma-ray bursts, while being the most luminous events in the universe (converting energy equal to the mass of our Sun into energy in one second), are too rare and brief to account for the number of observed UHECRs. TDEs, being intensely powerful for a period of weeks to months, are a possible candidate for the source of these cosmic rays. Astronomer Martin Rees predicted that there should be, on average, about one TDE per galaxy per 100,000 years. Farrar realized that if TDEs were in fact a major source of the cosmic rays, this figure would be in alignment with the number of rays we receive on Earth. Many colleagues dismissed the search for TDEs in the optical range as being too impractical to pursue, because their rate of occurrence is so much lower than those of similar events. One of Farrar`s graduate students, Sjoert van Velzen, agreed to work on the project with her for his master`s thesis.
AAA Lecture Series continues on page 12

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They used the Sloan Digital Sky Survey (SDSS) database which contains hundreds of millions of entries including stars, galaxies, and other celestial bodies. In order to fi nd flares, transitory events by definition, one has to show that a galaxy is much brighter at one time (while flaring) than before or after. The team limited their search to Stripe 82 of the SDSS, a region of the sky in which the same objects were observed 70 times each, over a nine year period, allowing them to see such variations. They also looked in optical bands instead of X-ray bands often used t o observe AGNs, because of the greater resolution and much larger sky coverage available. Stripe 82 contains about five million objects, half of which are galaxies. Van Velzen and Farrar identified flares (of any kind) by making difference images comparing the same galaxies viewed at different times. With this method, the y found 342 flaring galaxies in the stripe. At this point, regular AGNs as well as transient supernovae had to be eliminated by looking at the variability and positioning. Supernovae, since they can occur anywhere, are relativel y unlikely to be at the center of a galaxy. They then excluded galaxies of the type that tend to have AGNs, which, while possibl y excluding some TDEs, allowed greater certainty in those that were found. Lastly, AGNs have significant variability over the nine-year timescale, while TDEs are abrupt flares with little other variability. After finally removing those flares that had insufficient or poor quality data, two remained that could be identified as TDEs. In order to confirm the discovery, Farrar and

vanVelzen looked into other sky archives such as GALEX and CRTS. Both archives` data corroborated the SDSS evidence. The discover y of two TDEs in Stripe 82 is exciting because this is such a small area of sky, observed over a relativel y short time scale. If there were t wo seen just there, many more must exist within our range of observation. The knowledge that studying TDEs promises us is great. Since they depend strongly on the properties of the black hole causing them, we can learn about potential cosmic ray sources, black holes that are difficult to study in other wa ys, and the accretion disks that can form around them, in part the remnants of long -dead stars. Now that we know more about their properties, it should be easier to recognize them. The future holds much for us to learn about these strange and powerful celestial events. Professor Stephan Rosswog (Jacobs University, Germany) demonstrates the disruption of a white dwarf by an intermediate-mass black hole (1000 times the mass of the sun) online. NEXT MONTH IN EYEPIECE
Readers: Look what's coming in April's issue: Richard Brounstein explores WHAT IF a planet was entirely in da ylight all the time; Tom Ha eberle flies us to the Sun to prepare for the June 5th Venus transit event; Evan Schneider reviews the AMNH 2012 Isaac Asimov Memorial Debate: Faster Than the Speed of Light (the neutrino debate, of course); Stan Honda continues his series on photographic techniques; we`ll update NASA`s New Horizons mission to Pluto; AAA Briefs in Astronomy continue to inform us; Rich Rosenberg`s What`s Up in the Sky and more...

Amateur Astronomers Association PO Box 150253 Brooklyn, NY 11215. ADDRESS SERVICE REQUESTED

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