Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.aaa.org/EyepieceFiles/aaa/2011_03_March_Eyepiece.pdf Дата изменения: Sun Feb 22 20:31:02 2015 Дата индексирования: Sun Apr 10 03:40:03 2016 Кодировка: ISO8859-5 Поисковые слова: reflection nebula

Journal of the Amateur Astrono mers Association of New York March 2011 Volume 59 Number 3 ISSN 0146-7662

EYEPIECE
Dark Matter By Edward J. Fox
One of the greatest mysteries of science, dark matter, was probed F ebruary 4 in an AAA lecture at the AMNH by Dr. Neil Weiner, associate professor of physics at NYU's Center of Cosmology and Particle Physics . In a talk on "Illuminating Dark Matter --Uncover ing the Dark Universe," Weiner noted the mysteriousness of dark matter and dark ener gy, which together account for 96 percent of the universe: 74 percent dark ener gy, 22 percent dark matter. One obvious question is that if ther e's so much dark matter, how can it be so difficult to find and explain? Even though dark matter accounts for some 80 percent of all matter, the existence of dark matter can only be inferred, Weiner noted. The ma jor problem in detecting dark matter is that light doesn't interact with it. Or as he put it, "How do you find what you cannot see?" The first clue that dark matter exists is that it seems to exhibit the tug of gravity. In fact, it was about 75 years ago that astronomers studying distant galaxies found they had hundreds of times mor e gravitational pull than the mass of visible stars would warrant. Fritz Zwicky postulated the existence of dark matter in 1934 to account for evidence of "missing mass" in the orbital velocities of galaxy clusters. Over the years, mor e evidence as to the probable existence of dark matter came to substantiate the hypothesis. These observations included rotational speeds of galaxies, gravitational lensing of backgr ound objects by galDark Matter continued on page 5

Speakers Discuss Subjects at the Cutting Edge of Astronomy
Multiverses By Alan Rude
Speaking at the Hayden February 7, Dr. Brian Greene, physicist, string cosmologist and Columbia professor, gave a mind-bending yet lucid talk on how a range of parallel universes can emerge from current theoretical insights which attempt to explain the cosmos. In a talk on "The Hidden Reality: Parallel Universes and the Deep La ws of the Cosmos, " Greene was quick to note that no experiments or observations had proven the existence of parallel universes, or multiverses. That said, recent developments in physics and mathematics, especia lly string theor y, have led scientists to consider the possibility that ours is but one of many universes and that otherwise baffling observations can be explained within the multiverse framewor k. At the outset, Greene referr ed to his new book, "The Hidden Reality--Parallel Universes and the Laws of theCosmos" (Knopf, $29.95), wher e he describes nine types of parallel universes--of which our universe is just a part--that could r esult from the mathematics now being used to explain the workings of the cosmos. Because of time considerations, his lecture cover ed only thr ee: the "quilted multiverse," the "inflationary multiverse" and the "landscape multiverse." The quilted-patchwork multiverse is easiest to understand since it doesn't require a hea vy dose of higher mathematics. This structure depends on whether our universe is finite or infinite. When pressed, most scientists opt for "infinite." Within our part of the universe, we can obser ve a sphere of 82 billion light-years: the cosmic horizon adjusted for the expansion of space. Multiverses continued on page 5


Whats Up
By Tony Hoffman The Sky for March 2011
A Drop of Mercury. Mercury creeps into the evening sky in the second week of the month to start its best evening apparition of the year, appearing about 10 degrees below Jupiter and blazing at mag -1.3. It will quickly climb in the evening sky and pass Jupiter (which is gradually sinking towards the sunset) at midmonth, when Mercury will as bright as mag -1. It will be at its highest March 21, when it will be more than 10 degrees high a half-hour after sunset, shining at mag -0.3. From ther e it will fade rapidly and slip back into the solar glare. March's Constellations. Orion stands high in the southwest in the early evening, with Gemini and Procyon near the meridian and Sirius brilliant south. Taurus lies almost due west as Cassiopeia swings down into the northwest, trailed by Perseus and Auriga. Leo rises headfirst, followed by Virgo, carrying its trove of galaxies. Hydra, with its bright orange star Alphard, climbs in the southeast. Ursa Major swings up in the northeast, trailed by Arcturus. Saturn is in Virgo about 10 degr ees above Spica between the stars Eta and Theta Virginis. Saturn's ring system is gradually opening, now tilted about 9 degr ees from our line of sight. Messier Marathon. This is the best month to try a Messier marathon. Around the New Moon, it's possible-with clear, dark skies, an unobstructed horizon, proper equipment, lots of practice and willingness to stay up all night--to see all but one of the 109 Messier objects over the course of a night. March 4 New Moon at 3:46 p.m. March 6 Moon lies near Jupiter. March 12 First-quarter Moon at 6:45 p.m. March 16 Mercury lies near Jupiter. March 19 Full Moon at 2:10 p.m.; Moon at perigee, 221,565 miles from Earth, 3:09 p.m. March 20 Ver nal equinox at 7:21 p.m.; Moon lies near Saturn. March 21 Mercury is at greatest elongation in evening sky (see above). March 26 Last-quarter Moon at 8:07 p.m. March 31 Moon lies near Venus.
2

Sun Still Not Very Active
By Joseph A. Fedrick
I have been projecting the Sun's ima ge weekly to observe sunspot activity. I have, as usual, been using my 60mm f/15 achromatic r efractor and a 20mm eyepiece to project the Sun's ima ge onto a piece of paper and tracing sunspot positions. So far this year, the Sun has been rather inactive. I have seen, at most, up to a half dozen small, unimpressive sunspots on the solar disk at one time. Most of the time, I have seen only one or two barely visible sunspots, or else the Sun appears blank, with no spots at all. The appearance of the Sun's projected image this year contrasts starkly with what happened 11 years ago, in 2000. Then, the projected ima ge displayed numer ous spots. There wer e two distinct parallel bands of sunspots on the Sun's disk. Each band was parallel to the Sun's equator, one north and the other south. So far, I havent seen the Sun get that active during the present sunspot cycle. The present cycle is predicted to pea k in 2013. That would be a rather delayed peak. The last cycle had a double peak. I observed maximu m activity in 1999 and 2001. 2013 would be 12 years beyond the second peak of the last sunspot cycle. It seems the present cycle will be less active than the last. However, we might be treated to a few large sunspots in two years, and perhaps one or two violent, huge storms. This happened in 1859 during a sunspot cycle that apparently wasn't very active as a whole. A solar storm like the two stor ms of 1859 would cause cha os that could last weeks or months, unless technicians could protect our electronic infrastructure from the Sun's electromagnetic assaults. Perhaps they might do this by temporarily putting satellites and the electric power grid into shutdown mode while the stor ms pass. On the morning of February 15, I saw emer ge, on the otherwise inactive Sun, a large group of sunspots extending approximately one-tenth across the solar disk. Soon afterward, I heard ther e was a coronal mass ejection that caused auroral displa ys in Norwa y. I believe that this year, the Sun will remain mostly inactive, but with a few brief, intense spurts of high activity.


A Message from AAA President Richard Rosenberg
Hello members: March on the 5t Field on just your is finally her e, and with it a reviva l of ma ny of our observing sessions. We have Gr eat Kills in Staten Island h, Dana Center at the north end of Central Park on the 10th, Inwood Park on the 11th and 25th, Floyd Bennett the 18th and solar observing in Central Park on the 26th. Whether you'r e coming with scope, binoculars or eyes, get reacquainted with the sky.

Bart Fried, fa med r estor er of telescopes, spoke at last month's board meeting as an invited guest. He's offer ed us an 8-inch refractor if we can provide an observatory. We are currently investigating wher e such an observatory might be located. Board member Dan Harrison is cha iring this year's nominating committee, which nominates members for positions on the board. If you'd like to serve on the board, contact Dan at dsharry2@aol.com or 914 -762-0358. I was leafing through the Dover Edition of T. W. Webb's classic guide "Celestial Objects for Common Telescopes" when I discover ed that two illustrations were done by AAA members, Charles Cuevas (a 1955 photograph of Comet Ar end-Roland) a nd Al Kolkin (a photograph of a bolide in 1957). Do any of you r emember these members? Rich Rosenberg, president@aaa.org, (718) 522-5014

AAA Lecture March 4: ,,Searching for Exoplanets with Kepler
Dr. Andrea K. Dupree, senior astrophysicist at the Smithsonian Astrophysical Observatory, part of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., will address the AAA on Friday, March 4 on "Searching for Exoplanets with Kepler." The free public lectur e begins at 6:15 p. m. in the Kaufmann Theater of the AMNH. "For centuries, people ha ve wonder ed whether our Earth and the solar system are unique in the universe," Dupree observes. "Only 16 years ago, in 1995, the discover y of the first planet outside the solar system marked the beginning of an astonishing sequence of planetary detections from the ground. Several hundred exopla nets are now known to orbit their stars but all are larger than Earth. "However, this situation ma y soon cha nge. NAS A's Kepler satellite, launched in March 2009, is aimed at a 100-square-degr ee area of the sky in Cygnus, and carries out photometry with exquisite precision on a field containing mor e than 100,000 stars. Kepler will stare at these stars for several years in order to detect planetary transits with the goal of finding terrestrial planets in the "habitable zone," wher e liquid water and possibly life might exist. "Verifying planetary candidates with spectroscopy, high-resolution ima ging and modeling also comprises a critical part of the planet -search program. A number of planets and pla netary systems have been discover ed with Kepler, including a small rocky planet. In addition to detecting planetary transits, Kepler obtains a wea lth of infor mation on stellar variability, including studies of asteroseismology and gyrochronology. "This presentation will give an over view of the Kepler mission highlighting new r esults." Harvard-Smithsonian is the largest research institute dedicated to astronomy and astrophysics in the world. Dupree, who holds a Ph.D. from Harvard University in astrophysics, is an inter nationally recognized leader in stellar physics and ultraviolet astronomy, and is a member of the Kepler Science Tea m. She led the tea m making the first direct image of a star other than the Sun, and studies winds and mass loss in young and old stars. She's Lecture continued on page 11
3


The Complexities of the Human Eye that Enable Observing
By Katherine Avakian
Obvious vision-based aspects of observational astronomy are mirrored by astronomy-r elated aspects of human vision, a January 25 AMNH speaker stated. "Astronomy has been a vision-based science for thousands of years," prior to the development of photography in the first half of the 19th century and digital technologies in the 20th century, said Dr. Emily Rice, in a talk on "Astronomy and Vision," in conjunction with the museum's major exhibit on the brain. Rice, a postdoctoral researcher with the AMNH's Exopla net Group, said the eye developed "as an outgrowth of the brain," and was ther efore part of the central nervous system. She spelled out the basics of vision: "The retina is composed of light-sensitive cells (seven million cones and about 100 million rods) that convert detected light to electrica l signals (neural impulses) processed by the visual cortex in the brain." As the Space Theater darkened, Rice explained that the star projector, Universarium Model IX, uses fiber optics to project more tha n 9,000 stars, planets and deepsky objects onto the dome, simulating the night sky. At the same time, our eyes started adapting to the dark. She noted that when the eyes are exposed to a very dark sky, a large change occurs in the pupils in about four seconds. Ther eafter, the pupils continue to gradually dilate over the next half hour or so, enabling the viewer to see mor e deta il. Rice added that, unfortunately, as we age, the pupils do not dilate as much, diminishing one's ability to see fainter objects. In able, terns one, cup, the dome, major constellations beca me recognizprompting Rice to say the brain can recognize pateven better than computers. The Big Dipper was with thr ee stars in the handle and four stars in the the top stars in the cup pointing to the North Star. picturing something not right in fr ont of you --as another way in which the brain functions, and said other cultures have imagined the Big Dipper to be a wagon, a plough, a cart and a saucepan. Orions distinctive belt lea ding the eye to the brightest star in the sky, Sirius in Canis Major. Orion, containing the red star Betelgeuse, also displayed the various colors of stars, color in the astronomical sense being defined as "the relative intensities of differ ent wavelengths of light." Thus, blue stars such as Sirius, with the shortest wavelengths, are hottest, and red stars like Betelgeuse, with longer wavelengths, are coolest. The retina in huma ns, containing light-sensitive rods and cones, enables us to detect brightness and color. In his book, "Eyes and Ears," Seymour Simon explains, "Rod cells are sensitive to sha des of brightness and are used to see in black and white....Cone cells work best in bright light and let us see color....We use the cones more during the day and the rods more during the night." Rice spoke about the use of averted vision to better see faint objects such as the Andromeda Galaxy. Because rod cells "are more densely concentrated at the edge of your vision...if you look at a faint object and then you look away from it, looking at it out of the corner of your eye, it becomes noticeably brighter." Color vision was one of the last things to develop, Rice said. She also noted that our eyes have evolved to see in only a small segment of the much larger electroma gnetic spectrum. In anima ls, color vision evolved separately from that of huma ns, and creatures such as birds, insects and snakes can see beyond the visible spectrum into the infrared and ultraviolet.

Contacting the AAA
General club matters: president@aaa.org. Membership business, such as dues and change of addr ess: members@aaa.org. Eyepiece: editor@aaa.org. Lectures: lectures@aaa.org. Classes: classes@aaa.org. Seminar: seminar@aaa.org. Observing: president@aaa.org. Please visit us on the web at www.aaa.org.

But the Big Dipper is part of a larger constellation, Ursa Major, with the three handle stars comprising the bear's tail. The Iroquois also saw that star group as a bear, but interpreted the handle stars as three hunters in pursuit. Rice pointed out the use of ima gination-4


Dark Matter continued from page 1 axy clusters, such as the Bullet Cluster, and temperature distribution of hot gas in galaxies and galaxy clusters. To find proof of dark matter, Weiner humor ously said, "I draw pictures." He showed how his pictures illustrate the combinations of particle interactions in the study of particle physics. Through particle physics, scientists hope to find dark matter or proof of its existence. The process starts with collisions of neutrons to get protons, electrons and neutrinos. Neutrinos are difficult to detect. It's theorized that a neutrino doesn't interact with matter. The Sun is a massive generator of neutrinos. Every second, 100 billion neutrinos go through our thumbnail. Physics Nobelist Raymond Davis was the first scientist to detect solar neutrinos, the ghostlike particles produced in nuclear reactions that power the Sun. He detected only about one-third of the anticipated number of neutrinos. Davis' results threw astrophysics into an uproar, and, for nearly three decades, physicists have tried to resolve the so-called "solar neutrino puzzle." Experiments in the 1990s, using differ ent detectors, eventually confir med the solar-neutrino discr epancy. According to Weiner, Davis' findings led to a variety of new suppositions, or "crazy hypotheses." Imagine ther e are multiple types of neutrinos, only some of which can be detected. "Suppose three-quarters of solar neutrinos turn into something else," Weiner said. Many experiments continue to be carried out: the Submarine Neutrino Obser vatory, using heavy water; the study of Wea kly Interactive Massive Particles (WIMPS), and the Large Hadron Collider's search for the Higgs Boson particle. Scientists also study the possibility that we're moving through a "wind of dark matter." Weiner said ther e's no apparent relationship between dark matter and dark ener gy. "Many people ha ve gone down this path, including myself." He used the analogy of dark matter in a box. If you make the box bigger, you still have the same a mount of dark matter. But if you have dark ener gy a nd you ma ke the box (the universe) bigger, you get mor e dark ener gy.

As to alternate theories to account for dark matter, one is the modified gravity model, Modified Newtonian Dyna mics (MOND), which adjusts Newton's laws to create a stronger gravitational field when gravitational acceleration levels become tiny, such as near the rim of a galaxy. It's had some success in predicting galactic-sca le features, such as rotational curves of elliptical galaxies and dwarf elliptical galaxies. But it's fallen short in predicting galaxy-cluster lensing. After so many years of study, Higgs Boson particle is going to not finding it." He fully expects thing in the next couple of years. is ther e. Something is ther e." he stated, "Finding the be less surprising than scientists to find some"We know dark matter

Multiverses continued from page 1 Inside a given cosmic horizon--Gr eene's cosmic patch on the "patchwork quilt"--the number of particle arrangements, while enor mous, is nevertheless finite. Given a finite number of particle arrangements and infinite space, the particle arrangements will eventually repeat. In every collection of 10ЙГВ cosmic patches, there should be a patch that exactly replicates our own: the Milky Way, the solar system, the Earth and us. The inflationary multiverse is based upon the theory of inflationary cosmology which modifies the Big Bang theory by incorporating an extreme burst of colossally fast (inflation) expansion in the very early state of the cosmos. Inflation has proven critical to explaining puzzling aspects of the microwave background radiation, and at least one version of inflation theor y has hinted at the possibility of a structure that yields a very large number of parallel universes. Multiverses continued on page 12

The AAA's annual meeting is Wednesday, May 18 a t headquarters. Plan on coming!
5


Review: The Beauty of Saturn, Its Rings and Its Moons
By Alan Rude
Nicole Mortillaro, author of "Saturn--Exploring the Mystery of the Ringed Planet" (Firefly, $29.95), is a Canadian a mateur astronomer a nd children's book editor who's written a book for all ages about the glorious, ringed planet. Illustrated with beautiful and magnificent photographs from the early Pioneer and Voyager probes, the Hubble and especially the mor e recent Cassini-Huygens mission still under way, her effort has the look of a coffee-table book. What sets it apart from that genr e is the accompanying text, which is both clear and scientific (although her copy editor should have eliminated overuse of words such as "enigmatic"). In addition to Saturn, the book concentrates on its rings and moon systems. On the planet, Cassini-Huygens sighted what's believed to be the most violent stor m in the solar system, a mor e than 340 mph hurricane with an eye wall and vortex. There are splendid color photographs of the rings, which are far more complicated than ima gined. There ma y be millions of tiny moonlets in Saturn's ring. The section on the moons is the most inter esting part of the book. The celebrity her e is Titan, second largest in the solar system after Jupiter's Ganymede. On January 14, 2005, Huygens landed on Titan, sending back astonishing pictur es of the surface. The topography, which appears similar to Earth's mountains, is pictured in all its red-brown glor y. Ther e's also an image of Titan's liquidmethane lakes, looking like bodies of water as seen on Earth from an orbiting satellite. In the section "Curious Moons," Mortillaro gives us photographs of other inter esting and major Saturnian moons, such as Hyperion, resembling a giant sponge; pockmarked Phoebe, and Tethys with its unusually bright crater floors. The most inter esting of these lesser satellites is Enceladus. In 2005, when Cassini came within 99 miles of the moon, it collected ima ges of water vapor and ice particles erupting from the surface. It was discover ed that the temperature at Enceladus' South Pole was 100 degr ees and that ther e was evidence of simple
6

carbons. So ther e's a question whether Encela dus could harbor simple life. No mission has contributed as much as CassiniHuygens to the knowledge of the Saturn system, and in 2008 it was extended for another four years. Mortillaro outlines the scientific advances resulting from the mission, and has even mor e strikingly captured in splendid photographs the beauty of Saturn, its rings and its moons.

Amateur Photogs Sought for Solar Sail
NASA has formed a partnership with Spaceweather.com to solicit the amateur -astronomy community to submit the best ima ges of the orbiting NanoSail-D solar sail. NanoSail-D unfurled the first-ever 100-squarefoot solar sail in low-Earth orbit January 20. To encourage obser vations of NanoSail-D, Spaceweather.com is offer ing $500, $300 and $100 prizes. The contest is open to all types of ima ges, including, but not limited to, telescopic captures to wide-field ca mera shots of solar-sail flares. If NanoSail-D's in the field of view, the ima ge is eligible. The solar sail, about the observable from early March the atmospher e and disintegr until NanoSail-D re-enters http://www.nanosail.org. size of a large tent, will be to late May before it enters ates. The contest continues Earth's atmospher e. Info:

Photo Contest Winners--The European Southern
Observator y announced winners of its 2010 astrophotography contest. The competition invited amateurs to dig through ESO archives and transfor m gray-scale scope observations into full-color ima ges. Igor Cheka lin, from Russia, won the grand prize, a trip to ESO's Ver y Large Telescope in Paranal, Chile, for a shot of the M78 nebular complex in Orion. He also submitted the secondhighest-rated ima ge, galaxies NGC 3166 and NCG 3169. The highest-ranked photos will be on www. eso.or g as Photo Releases or Pictures of the Week.


Briefs: Kepler Data Boost Number of Possible Exoplanets
NASA unveiled a wealth of new data from its planetseeking Kepler space telescope last month, observations that significantly increase the number of possible alien planets and identify potential Earth-size worlds. More than 500 exoplanets have been discover ed, but that could mor e than double if all candidate exopla nets from new Kepler data are confir med. Amid 1,200 possible alien worlds, Kepler has found 68 potentially Earth-size planets and 54 candidates in the habitable zone, a region wher e liquid water could exist on a planet's surface. Some candidates could even ha ve moons with liquid water. Five planetary candidates are near Earth size and orbit in the habitable zone of their stars. The data also reveal that smaller worlds and multi-planet systems may be mor e common than thought. Kepler has also discovered a solar system in which six planets are orbiting a Sunlike star, with five in close configuration. Few stars have been observed with planetary arrangements like our solar system. The smallest planet is about 2.3 times Earth mass. None of the exoplanets are inside the habitable zone. Astronomers ma de the find from Kepler ima ges of cha nging brightness of the system's star, Kepler-11, as the pla nets passed in front of it. The discovery of five sma ll pla nets with close orbits around the star, with another planet farther out, was unexpected. Kepler-11 is about 2,000 lightyears away. The system is compelling because of the number of planets around the host star, their relatively sma ll sizes and their tightly packed orbits. The discovery validates a powerful new method to measure pla net mass. The five inner pla nets are 2.3 to 13.5 times Earth mass. Their orbital periods are 10 to 47 days, which mea ns all five planets would fit inside Mercury's orbit. The sixth planet has an undeter mined mass, but is larger than the other five. It orbits ever y 118 Earth days. Of the six planets, the most massive are potentially like Neptune and Uranus, but the thr ee lowest-mass planets are unlike anything in our solar system. Before detection of the Kepler-11 system, astronomers had size and mass calculations for only three exoplanets smaller than Neptune. Now, measurements from a single pla netary system have a dded five mor e, and they'r e a mong the sma llest. All six planets have densities lower than Earth's. This implies most of their volumes are ma de of light elements. The inner two could be mostly water, with possibly a thin skin of hydrogen-helium gas on top. The ones farther out ha ve densities less than water, which seems to indicate significant hydr ogen-helium atmospher es. This was surprising, since it's hard for small, hot pla nets to hold onto a lightweight atmospher e. Close proximity of the inner planets mea ns they likely didn't for m where they are now. A new instrument will help NASA's Kepler spacecraft confir m and characterize potential alien planets. On the drawing boards is a new pr ecision spectrograph instrument, called HARPS-North. HARPS stands for "High-Accuracy Radial Velocity P lanet S earcher." This spectrograph is designed to detect the tiny radial velocity signal induced by planets as small as Earth if they orbit close to their star. Kepler provides the size of a planet, based on the amount of light it blocks when it passes in front of its star. Scientists now need to measure planetary masses. That will allow them to distinguish rocky pla nets and water worlds from ones dominated by atmospheres of hydrogen and helium. HARPS-N will partner with Kepler to characterize worlds enough like Earth that they might be able to support life as we know it. HARPS -N's measur ements are expected a year from now. Hubble has found whats likely to be the most distant object ever seen in the universe, 13.2 billion years away. That's roughly 150 million years longer than the previous record holder. (The age of the universe is 13.7 billion years.) The tiny, dim object is a compact galaxy of blue stars that existed 480 million years after the Big Bang. New data show the rate of star birth in the early universe gr ew dra matically, incr easing by about a factor of 10 from 480 million years to 650 million years after the Big Bang. Astronomers don't know when the first stars appeared. The object was found when astronomers looked at Hubble infrared data. The galaxy appears as a faint dot of starlight, too young and small to have the fa miliar spiral shape of galaxies in the loca l universe. Although its stars can't be resolved, evidence suggests it's a compa ct galaxy of hot stars for med 100 million-200 million years earlier from gas trapped in a pocket of dark matter. The proto-galaxy is only visible at the farthest infrared wavelengths observable by Hubble. NASAs next-generation space telescope could conContinued on page 8
7


Briefs: Sun Unleashes Strongest Flare in Four Years
Continued from page 7 fir m the existence of the oldest galaxy yet seen and peer back even further in time. The infrared James Webb Space Telescope (JWST), powerful successor to Hubble, which could launch in fall 2015, will look back even further in time, to just a few hundr ed million years after the universe's birth. Hubble's capabilities max out at about 480 million years after the universe's birth, but JWST should be able to see objects that formed 200 million300 million years after the Big Bang. The first stars may have come together at about 200 million years. JWST should provide data from when galaxies wer e coming together. The Sun unleashed its strongest solar flare in four years February 14, hurling a massive wave of charged particles from electrified gas toward Earth. A flash of radiation hit Earth in a matter of minutes, followed by a coronal mass ejection. The flare trigger ed a geoma gnetic storm in our magnetic field that interrupted radio communications and GPS systems. Satellites and power grids could also be affected. On February 13, sunspot 1158, which is growing rapidly, unleashed the strongest solar flare of the year. The mega flare was the first class X flare to occur in the new solar cycle of activity, which began last year. Meanwhile, the chief of the National Oceanic and Atmospher ic Administration (NOAA) said February 19 that space weather could pose serious problems on Earth in coming years. A sever e solar storm has the potential to take down telecommunications and power grids, and the country needs to be better prepared, NOAA a dministrator Jane Lubchenco told the a nnual meeting of the Amer ican Association for the Adva ncement of Science in Washington. "This is not a matter of if, it's simply a matter of when and how big," Lubchenco said of the potential for a danger ous solar flare. The space-weather threat is becoming direr as the Sun ramps up toward solar maximum, predicted for around 2013. An artificial crater on comet Tempel 1 created in 2005 by a NASA spacecraft took center stage in new photos released after another probe revisited the comet. The intentional scar on the comet was created by the Deep Impact mission, which dropped a small probe to see what the comet was made of. The Stardust spacecraft flew by Tempel 1 February 14. Ther e's a crater with a
8

sma ll mound in the center, and it appears that some ejecta went up and came right back down. This indicates the cometary nucleus is fragile based on how subdued the crater is. It also mea ns Tempel 1's ma n-ma de crater partially healed itself as the ejecta settled and refilled part of the depression. High-res Stardust photos clearly show the crater created during the Deep Impact collision. The crater is 492 feet across and is tucked between two larger craters that predate Deep Impact. Tempel 1 is 3.7 miles wide and completes one trip around the Sun every five and a half years. Deep Impact smacked it with an 800-pound copper probe. Stardust's main mission was to observe how Tempel 1 has changed since then. It flew within 110 miles of Tempel 1 and collected infor mation on its atmospher e. Stardust also recor ded data on the amount of dust cloud around the comet. It apparently took a beating as it zoomed past Tempel 1 at 24,300 mph, passing through waves of particles as it flew through the cloud around the comet. First results from the ESAs Planck mission reveal clues about how the universe began, including never befor e-seen distant galaxy clusters and echoes of the Big Bang. The spacecraft's initial surveys of the entir e sky produced much new data. Planck found thousands of new dusty cocoons wher e stars are forming, as well as some of the most massive galaxy clusters. The mission aims to garner some of the most detailed data to date on the cosmic microwave background (CMB). By studying CMB fluctuations, researchers hope to glea n info about the origin and evolution of the universe, including what ma in ingr edients wer e present at its beginnings. Planck takes measurements between infrared and radio that reveal an otherwise invisible population of galaxies shrouded in dust, billions of years in the past. These galaxies for med stars at huge rates, 10-1,000 times higher than we see in our own galaxy, and are some of the coldest places in the universe. Planck's new catalog includes some of the coldest dusty star nurseries ever seen, with temps as low as seven degr ees above absolute zero. The catalog also contains some of the most massive gala xy clusters known, including newfound ones. The most massive of these holds the equivalent of 1 million billion Suns' worth of mass. As yet, scientists can't see beyond the CMB, which blocks the first 380,000 years of the Continued on page 9


Briefs: Solitary Stars in Early Universe Werent the Rule
Continued from page 8 universe from view. However, scientists hope Planck can eventually look beyond this to for mation of the universe's first large-scale structures. Data indicate material obscuring the universe's birth is dust grains, spinning at tens of billions of times per second, most likely set in motion by collisions with fast-moving atoms or packets of ultraviolet light. Astronomers have long believed the early universe was populated by huge, solitary stars. But a new study suggests these loners wer e mor e the exception. Astrophysicists pushed the timeline of early star for mation simulations further than befor e. They found most early protostars, precursors to full-blown stars, likely for med in tight systems of multiple stars. Some primor dial multiple-star systems ma y have ha d separations as small as between the Earth and the Sun. Tests revealed isolated stellar disks wer e likely to fragment because after becoming so hea vy and massive, they became gravitationally unstable. They then collapsed in on themselves and for med other protostars. The simulation also suggests that if conditions wer e right, some of the first stars could have been ejected from their local stellar groups over time. As each protostar accreted mor e material, it radiated heat, eventually ionizing the cloud and ending the fragmentation. The initial protostar remained largest, still well within the high-mass range predicted by the previous model. Instea d of existing in isolation, however, it found itself accompanied by a small group of low -mass companions. The accr etion of mass takes hundr eds of thousands of years. This simulation ends at 10,000. An unusual spiral galaxy with a flat, pancake-like shape is missing the trademark central bulge common to other galaxies. NGC 3621 appears to be a classical spir al galaxy at first. But a closer look reveals its lack of a central bulge ma kes it a "pure-disk galaxy." The galaxy's flat shape indicates it has yet to come face-to-face with another galaxy, since a violent galactic smash-up would disturb the thin disk of stars and create a small bulge at the galaxy's center. Recent research suggests pure-disk galaxies may be fairly common. NGC 3621 is about 22 million light-years away in Hydra. It's comparatively bright and can be detected with moderate-size scopes. Dunes in the north of Mars aren't frozen in time as some have thought. Their sands can shift both slowly and quickly. These dune fields cover an area the size of Texas in a band around Mars at the edge of its north polar cap. Most data suggested they wer e fairly static, perhaps crusted over when winds wer e much stronger than today. But befor e-and-after pictures from the Mars Reconnaissance Orbiter over two Martian years, the equivalent of four Earth years, reveal a differ ent story. What's behind these shifting sand dunes is twofold: the seasonal coming a nd going of "dry ice" and surprisingly powerful gusts of wind. About 30% of carbon dioxide in the atmospher e freezes out of the atmospher e and blankets whatever pole is experiencing winter. It changes back to gas in the spring. The gas flow destabilizes sand on the dunes, causing avalanches and creating alcoves, gullies and sand aprons. The level of erosion in just one Mars year was surprising. Mars poles might not be the only place wher e water ice might be hidden. Scientists now suggest it could also lurk at the equator in craters. Radar scans of equatorial hills suggest they might harbor as much water as a polar ice cap. Ther e appears to be ice-rich material buried at the bottom of at least 38 craters near the equator. This material appears similar to what's thought to be buried ice at mid-latitude craters in both hemispher es. That water ice exists near the equator raises questions about recent climate change. Findings confir m that Mars experiences dramatic climate swings whenever the tilt of its poles in r elation to the Sun shifts. Scientists are monitoring locations along the equator for new meteor impa cts that could expose buried ice. NASAs Mars Science Laboratory (MSL) mission needs an $82 million infusion to ma intain its late November launch date after development of the $2.47 billion rover exhausted program funding reserves last year. The 3% cost incr ease was attributed to problems developing mobility systems, avionics, radar and drill, and delays completing an instrument suite to sniff the air for carbon-containing compounds. With MSL slated for delivery to Cape Canaveral in June, funding reserves must be restored to gird against further development or test problems that could cause the rover to miss a threeContinued on page 10
9


Briefs: Laser to Pave Way for New Adaptive Optics System
Continued from page 9 week launch window beginning November 25. Postponing MSL's launch again isn't an option. To help take extra sharp ima ges of space, a telescope in Chile is firing a mega-laser, made up of five bea ms, into the night sky. The sodium laser is part of a telescope and is the cornerstone for a next-generation adaptive-optics system. The laser is a thick, bright yellow bea m of light. The system consists of a single 50 watt laser split into five bea ms that create a five-point "star" grouping when fired 56 miles into the sky. Computers use the laser to build a real-time, threedimensional view of the atmospher e and use that data to cha nge the shape of the telescope's mirror to cancel out blurring effects about 1,000 times per second. At ground level, the laser is visible to the unaided eye due to scattering effects. The system begins observations in 2012. NASA last month released the first 360-degr ee view of the entire Sun. The photo came courtesy of the agency's twin STEREO (Solar TErrestrial RElations Observator y) spacecraft, which aligned exactly opposite each other on opposite sides of the Sun to capture the ima ge. The ability to see the whole Sun, front to back, will allow scientists to better understand complicated solar-weather patterns and ma ke plans for future robotic or manned spacecraft missions throughout the solar system. From Dece mber 13-22, a mob of icy comets pelted the Sun in an extraordinary storm. During that time, the Solar and Heliospheric Observatory (SOHO) detected 25 comets diving into the Sun. Sungrazers aren't uncommon, but 25 in 10 days is unprecedented. The small comets wer e about the size of a room or a house. Scientists think the stor m could be a signal that a much larger sungrazer is to come, one that people might be able to see with the na ked eye during the day. A giant star nearing its death is surrounded by an unusual cloud of gas and dust that is generally only found around baby stars, as revea led by a new 3-D imaging technique. The star, HD 62623, is a supergiant. Unlike almost all stars of that class, HD 62623 is surrounded by a dense shr oud of plasma and dust. Hot su10

pergiant stars are extr emely bright and radiate so strongly that their stellar wind would nor mally prevent matter from condensing as dust. Astronomers conclude that a companion star, with a mass roughly equivalent to the Sun, is likely the key to HD 62623's strange babylike features and the reason for the uncharacteristic disk around HD 62623. This companion wasn't dir ectly detected because its brightness is thousands of times lower than the primary star, but its presence is betrayed by a central cavity that lies between the gas disk and the central star. A new study has pinpointed the lower limit of dark matter needed to ignite frenzied star formation: a mass equal to 300 billion Suns. While dark matter has yet to be directly observed, it's a vital ingr edient for galaxies in star formation. The 300 billion solar masses' worth of dark matter is about 10 times less than the a mount previously estimated. If one starts with too little dark matter, a developing galaxy would peter out. If ther e's too much, gas doesn't cool efficiently to form one large galaxy, and you end up with lots of sma ller galaxies. But if you have the just the right a mount of dark matter, a galaxy bursting with stars will pop out. Such ga laxy characteristics as brightness and stellar mass are directly related to the size of their dark matter halo. Scientists studied a patch of sky the size of the Moon in Ursa Major to make their discovery. This wedge of sky is idea l for studying objects outside our galaxy because of low dust contamination from the Milky Way. A giant ring of black holes has been viewed by several scopes across differ ent parts of the light spectrum. Two interacting galaxies, known collectively as Arp 47, about 430 million light-years from Earth, set the stage for the view. Arp 147 contains the mixed-up leftovers from the collision of a spiral galaxy and an elliptica l galaxy that unleashed an expanding wave of star formation. The wave of stars creates the ring effect. But these stars are short-lived, lasting no mor e than a few million years befor e they explode as super novas or collapse into black holes. The black holes pepper the ring, with their powerful X-ray emissions appearing as bright pink specks. Another galaxy is present in the image, appearing as a dull red, along with a bright star and distant quasar. The most intense period of star for mation ended an estimated 15 million years ago.


Events on the Horizon March 2011
M: me mbers; P: open to the public; T: bring your telescopes, binoculars, etc.; C: cancelled if cloudy; HQ: at AAA headquarters, Downtown Community Center, 120 Warren St. For directions to AAA observing events, check the club's website, www.aaa.org. Thursday, March 3, 6:30-8:30 p. m. Recent Advances in Astronomy Seminar, M, HQ The seminar now incorporates the Observers' Group. Next date: April 7. Friday, March 4, 6:15 p. m. AAAs annual John Marshall Memorial Lecture, P, AMNH, FREE Dr. Andr ea K. Dupree, senior astrophysicist at the Smithsonian Astrophysical Observatory, will speak on "Searching for Exopla nets with Kepler" in the Kaufma nn Theater of the AMNH. Saturday, March 5, 7:30-11 p. m. Observing at Great Kills Gateway National Park, Staten Island, P, T, C Next date: April 2, 8-11 p. m. Monday, March 7, 7:30 p. m. LeFrak Theater, AMNH Annual Isaac Asimov Memorial Debate, P, AMNH Can the universe be explained with a single, unifying theory? Hayden dir ector Neil deGrasse Tyson will moderate a panel consisting of Katherine Freese, professor of physics at the University of Michigan; Jim Gates, professor of physics at the University of Maryland-College Park; Janna Levin, professor of physics and astronomy at Barnard College; Marcello Gleiser, professor of physics and astronomy at Dartmouth College; Bria n Greene, professor of physics and mathematics at Columbia University; and Lee Smolin, theor etical physicist at the P erimeter Institute for Theor etical Physics. Thursday, March 10, 6:30-8 p. m. Observing at Charles A. Dana Discovery Center, Central Park North at Lenox Avenue, P, T, C Preceded by presentation on late winter/early spring sky. Fridays March 11 and 25, 8-11 p. m. Observing at Inwood Hill Park, Manhattan, P, T, C Next dates: April 8, 22. Friday, March 18, 8-10 p, m. Observing at Floyd Bennett Field, Brooklyn, P, T, C Next date: April 15. Saturday, March 26, 10-noon Solar Observing at Central Park, P, T, C At the Conservator y Water. Next date: April 30. Lecture continued from page 3 published hundr eds of papers and articles, and edited several books. Dupree has also been involved in the design of satellite telescopes. The speaker is a past president of the Amer ican Astronomica l Society. She's led and served on many committees of the National Academy of Sciences, NASA and others to deter mine the course of astronomical research in the U. S. and other countries. Dupree was earlier associate director of the Harvard-Smithsonian, the first woma n and youngest person in that post, and ser ved as hea d of the Solar, Stellar and Planetary Physics Division. Other upcoming lectures are: April 1, Greg Matloff, New York City College of Technology, "Regr eening the Earth Using Space Resources," and May 6, David J. Thompson, NASA, "Exploring the Extreme Universe with the Fer mi Gamma -ray Space Telescope." Duprees talk will be the clubs annual John Marshall Memor ial Lecture, which honors a past president and executive director of the AAA who was instrumental in its growth. Marshall died in 1997.
11


Multiverses continued from page 5 This theory posits eter nal inflation occurring in the inflaton field; physicists drop the second i in na ming the field as a matter of convention. The inflaton is a superhigh ener gy field undergoing inflationary expansion. From time to time parts of the inflaton field experience a decrease in energy. Such portions will transit out of the super-fast expansion, converting the inflaton field's ener gy level into familiar particles, photons, quarks, stars, galaxies and planets. Greene used the description of a block of S wiss cheese: The cheesy part is the high-ener gy inflaton field, occupying most of what he calls the gr eater cosmos, and the holes are lower-ener gy regions like ours. He calls these holes "bubble universes," ours being only one of a huge number of them. Greene asserted a differ ence of perspective by observers inside and outside a bubble universe. Because of the relativistic perception of time and space, outside observers will see a finite bubble universe and experience endless time. But from the point of view of observers inside the bubble, space will appear infinite. We ca n ther efor e think of ourselves as occupying one

of a vast number of universes in an inflationary cosmos, each of which has its own collection of quiltedpatchwork universes. Thus, there are not only parallel universes but parallel, parallel universes. The landscape multiverse was the final parallel universe Greene discussed. He introduced string theory, which many physicists consider as the basis for a "theory of ever ything." String theor y proposes as yet unseen extra dimensions. The mathematics of the theory dicta te that these extra dimensions take the for m of Calabi-Yau shapes (after their discover ers). Ther e are an incomprehensible number of these shapes: 10 . Greene believes that when string theor y and inflationary cosmology are mer ged, all of string theor y's possible shapes for extra dimensions are distributed throughout the cosmos and deter mine properties specific to each universe. The big question is: Do any such universes have similar physical laws to ours? Although, with present resources, we cannot come close to testing, by experiment and observation, the existence of the multiverses Greene described--a nd perha ps we never can--by trusting in mathematics to lead us to hidden truths about the wor kings of our universe, we'll follow a path that has led time and again to major discoveries in science in general and physics in particular.

Amateur Astronomers Association Gracie Station P. O. Box 383 New York, NY 10028

If you havent renewed your membership, this is your last issue of Eyepiece!

Forwarding and Address Correction Requested 12

First Class