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Cosmic Heavyweights in Free-
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The most crowded collision o
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4/17/09
| Description |
The most crowded collision of galaxy clusters has been identified by combining information from three different telescopes. This result gives scientists a chance to learn what happens when some of the largest objects in the universe go at each other in a cosmic free-for-all. Using data from NASA's Chandra X-ray Observatory, Hubble Space Telescope and the Keck Observatory on Mauna Kea, Hawaii, astronomers were able to determine the three-dimensional geometry and motion in the system MACSJ0717.5+3745 (or MACSJ0717 for short) located about 5.4 billion light years from Earth. The researchers found that four separate galaxy clusters are involved in a triple merger, the first time such a phenomenon has been documented. Galaxy clusters are the largest objects bound by gravity in the universe. In MACSJ0717, a 13-million-light-year-long stream of galaxies, gas and dark matter -- known as a filament -- is pouring into a region already full of galaxies. Like a freeway of cars emptying into a full parking lot, this flow of galaxies has caused one collision after another. Image Credit: X-ray (NASA/CXC/IfA/C. Ma et al.), Optical (NASA/STScI/IfA/C. Ma et al.) |
| Date |
4/17/09 |
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Uranus from Earth
| title |
Uranus from Earth |
| date |
07.11.2004 |
| description |
An infrared composite image of the two hemispheres of Uranus obtained with Keck adaptive optics. The component colors of blue, green, and red were obtained from images made at near infrared wavelengths of 1.26, 1.62, and 2.1 microns respectively. The images were obtained on July 11 and 12, 2004. The representative balance of these infrared images which were selected to display the vertical structure of atmospheric features gives a reddish tint to the rings, an artifact of the process. The North pole is at 4 o'clock. *Image Credit*: Lawrence Sromovsky, University of Wisconsin-Madison/ W. M. Keck Observatory |
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Gamma-Ray Burst Found to be
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| Title |
Gamma-Ray Burst Found to be Most Energetic Event in Universe |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. A team of astronomers has announced that a recently detected gamma-ray burst was as bright as the rest of the universe, releasing a hundred times more energy than previously theorized. The team measured the distance to a faint galaxy from which the burst, designated GRB 971214, originated. It is about 12 billion light-years from Earth. The astronomers used a suite of satellites and ground-based telescopes to follow the burst. This Hubble image of the GRB 971214 field was taken about four months after the burst, well after the afterglow had faded away. The extremely faint and distant object marked with an arrow is the host galaxy of the gamma-ray burst. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1998/17/text/ ] |
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Double Asteroid 90 Antiope
| Title |
Double Asteroid 90 Antiope |
| Explanation |
This eight-frame animation is based on the first ever images [ http://www.boulder.swri.edu/~merline/press/ ] of a double asteroid [ http://www.boulder.swri.edu/~merline/press/release.txt ]! Formerly thought to be a single enormous chunk of rock, asteroid 90 Antiope [ http://cfa-www.harvard.edu/iau/lists/ NumberedMPs00001.html ] resides in the solar system's [ http://space.jpl.nasa.gov/ ] main asteroid belt [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ asteroids.html ] between Mars and Jupiter. Now, these premier images reveal Antiope to actually consist of two 50 mile wide asteroids separated by about 100 miles. Like weights on each end of an elastic string, the pair mutually orbit [ http://hyperphysics.phy-astr.gsu.edu/hbase/ orbv.html#bo ] their center of mass, or balance point in the space between them, once every 16.5 hours. Binary asteroids and asteroids with moons [ http://antwrp.gsfc.nasa.gov/apod/ap991014.html ] are believed to be rare, but observations of their orbits allow a direct determination of asteroid masses and densities. Surprisingly, Antiope and known [ http://www.cfht.hawaii.edu/News/PR_001026/ ] asteroid-moon [ http://antwrp.gsfc.nasa.gov/apod/ap990807.html ] systems are found to have densities closer to ice than rock, despite their relatively dark and unreflective surfaces. These sharp images were made at the Keck Observatory atop the Hawaiian volcano Mauna Kea using newly developed adaptive optics [ http://www.mtwilson.edu/Science/ AdapOpt/Overview/ ] technology to overcome the blurring effect [ http://antwrp.gsfc.nasa.gov/apod/ap000725.html ] of Earth's atmosphere. |
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LkHa101: The Hole in the Dou
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| Title |
LkHa101: The Hole in the Doughnut |
| Explanation |
You'd need a really big cup of coffee with this doughnut [ http://www.physics.usyd.edu.au/~gekko/ doughnut.html ] ... because the hole in the middle is about a billion kilometers across. Centered on the Sun, a circle that size would lie between the orbits of Mars and Jupiter. In fact, this doughnut is known to surround a massive newborn star cataloged as LkHa 101 which lies in the constellation Perseus [ http://www.allthesky.com/constellations/perseus/ constell.html ]. Imaged in infrared light [ http://cfa-www.harvard.edu/newtop/whatsnew.html ], the tantalizing torus-shaped cloud of gas and dust [ http://stardust.wustl.edu/IDPIntro.html ] is slightly tilted to our view. The cloud's material may well be the ingredients for the formation of a distant solar system [ http://www.spaceart.org/lcook/extrasol.html ]. A bright source of ultraviolet light [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/ multiwavelength.html ], the hot young star itself is much fainter in the infrared and so not visible in this picture. Still, the star's presence is indicated as its intense stellar wind and radiation has apparently carved out the doughnut's hole. This premier close-up of a stellar system in formation was accomplished by adapting a powerful observational technique called interferometry [ http://www.sciam.com/2001/0301issue/0301armstrong.html ] to planet Earth's largest single mirror telescope, the 10 meter Keck [ http://www2.keck.hawaii.edu:3636/ ]. |
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A Year of Dark Cosmology
| Title |
A Year of Dark Cosmology |
| Explanation |
We live in the exciting time when humanity discovers the nature [ http://antwrp.gsfc.nasa.gov/debate/debate98.html ] of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears to have astronomers groping in the dark. Dark matter [ http://www.sciam.com/specialissues/0398cosmos/0398rubin.html ] and dark energy [ http://www.lbl.gov/Science-Articles/Archive/dark-energy.html ] are becoming accepted invisible components of our universe, much like oxygen [ http://pearl1.lanl.gov/periodic/elements/8.html ] and nitrogen [ http://pearl1.lanl.gov/periodic/elements/7.html ] have become established invisible components of Earth-bound air [ http://www.dep.state.pa.us/earthdaycentral/97/air_teachers/naturally.htm ]. In comprehending [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/bitsff.html ] the nature and origin of the formerly invisible, however, we are only just exiting the cosmological dark age [ http://library.thinkquest.org/2834/gather/darkage/darkage.htm ]. Relatively unexplored concepts such as higher spatial dimensions [ http://antwrp.gsfc.nasa.gov/apod/ap010418.html ], string theories [ http://superstringtheory.com/ ] of fundamental particles [ http://particleadventure.org/ ], quintessence [ http://physicsweb.org/article/world/13/11/8/1 ], and new forms of inflation [ http://www.astro.ucla.edu/~wright/cosmo_04.htm ] all vie for cornerstone roles in a more complete theory [ http://www.sciam.com/2001/0101issue/0101peebles.html ]. As understanding invisible air has led to such useful inventions as the airplane [ http://www.wam.umd.edu/~stwright/WrBr/taleplane.html ] and the oxygen mask [ http://www.avweb.com/articles/howoxy.html ], perhaps understanding dark matter [ http://chandra.harvard.edu/xray_astro/dark_matter.html ] and dark energy [ http://xxx.lanl.gov/abs/astro-ph/9811454 ] can lead to even more spectacular and useful inventions. Pictured above [ http://www2.keck.hawaii.edu:3636/realpublic/gen_info/kiosk/gallery.html ], three of the largest optical telescopes [ http://www.seds.org/billa/bigeyes.html ] (Keck I, Keck II [ http://www2.keck.hawaii.edu:3636/realpublic/gen_info/kiosk/index.html ], and Subaru [ http://www.naoj.org/ ]) prepare to peer into the dark and distant universe. |
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A Sharper View of a Tilted P
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| Title |
A Sharper View of a Tilted Planet |
| Explanation |
These sharp views [ http://www2.keck.hawaii.edu/news/science/uranus/ index.html ] of tilted gas giant Uranus [ http://www.nineplanets.org/uranus.html ] show dramatic details of the planet's atmosphere and ring system [ http://ringmaster.arc.nasa.gov/uranus/uranus.html ]. The remarkable ground-based images [ http://www.news.wisc.edu/10402.html ] were made using a near-infrared camera and the Keck Adaptive Optics system to reduce the blurring effects of Earth's atmosphere. Recorded in July, the pictures show [ http://www.news.wisc.edu/newsphotos/ uranus2.html ] two sides of Uranus (careful how you pronounce [ http://www.nineplanets.org/say/uranus.au ] that ...). In both, high, white cloud features are seen mostly in the northern (right hand) hemisphere, with medium level cloud bands in green and lower level clouds in blue. The artificial color scheme lends a deep reddish tint to the otherwise faint rings [ http://antwrp.gsfc.nasa.gov/apod/ap030115.html ]. Because of the severe tilt of its rotational axis, seasons on Uranus [ http://www.haydenplanetarium.org/hp/vo/ava/avapages/ P0418uranseas.html ] are extreme and last nearly 21 Earth years on the distant planet [ http://nssdc.gsfc.nasa.gov/ planetary/factsheet/uranusfact.html ]. Uranus is now slowly approaching its southern autumnal equinox - the beginning of fall in the southern hemisphere - in 2007. |
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Circle of Ashes
PIA08041
Infrared Array Camera (IRAC)
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| Title |
Circle of Ashes |
| Original Caption Released with Image |
Circle of Ashes This plot tells astronomers that a pulsar, the remnant of a stellar explosion, is surrounded by a disk of its own ashes. The disk, revealed by the two data points at the far right from NASA's Spitzer Space Telescope, is the first ever found around a pulsar. Astronomers believe planets might rise up out of these stellar ashes. The data in this plot, or spectrum, were taken by ground-based telescopes and Spitzer. They show that light from around the pulsar can be divided into two categories: direct light from the pulsar, and light from the dusty disk swirling around the pulsar. This excess light was detected by Spitzer's infrared array camera. Dust gives off more infrared light than the pulsar because it's cooler. The pulsar, called 4U 0142+61, was once a massive star, until about 100,000 years ago, when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a "fallback disk," now circling the leftover stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born. The data have been corrected to remove the effects of light scattering from dust that lies between Earth and the pulsar. The ground-based data is from the Keck I telescope atop Mauna Kea, Hawaii. |
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Circle of Ashes
PIA08041
Infrared Array Camera (IRAC)
…
| Title |
Circle of Ashes |
| Original Caption Released with Image |
Circle of Ashes This plot tells astronomers that a pulsar, the remnant of a stellar explosion, is surrounded by a disk of its own ashes. The disk, revealed by the two data points at the far right from NASA's Spitzer Space Telescope, is the first ever found around a pulsar. Astronomers believe planets might rise up out of these stellar ashes. The data in this plot, or spectrum, were taken by ground-based telescopes and Spitzer. They show that light from around the pulsar can be divided into two categories: direct light from the pulsar, and light from the dusty disk swirling around the pulsar. This excess light was detected by Spitzer's infrared array camera. Dust gives off more infrared light than the pulsar because it's cooler. The pulsar, called 4U 0142+61, was once a massive star, until about 100,000 years ago, when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a "fallback disk," now circling the leftover stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born. The data have been corrected to remove the effects of light scattering from dust that lies between Earth and the pulsar. The ground-based data is from the Keck I telescope atop Mauna Kea, Hawaii. |
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