May21
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Observations with NASA’s Chandra X-ray Observatory have provided the first X-ray evidence of a supernova shock wave breaking through a cocoon of gas surrounding the star that exploded. This discovery may help astronomers understand why some supernovas are much more powerful than others. On Nov. 3, 2010, a supernova was discovered in the galaxy UGC 5189A, located about 160 million light years away. Using data from the All Sky Automated Survey telescope in Hawaii taken earlier, astronomers determined this supernova exploded in early October 2010 (in Earth’s time-frame). This composite image of UGC 5189A shows X-ray data from Chandra in purple and optical data from Hubble Space Telescope in red, green and blue. SN 2010jl is the very bright X-ray source near the top of the galaxy. A team of researchers used Chandra to observe this supernova in December 2010 and again in October 2011. The supernova was one of the most luminous that has ever been detected in X-rays. The results of these observations were published in a paper that appeared in the May 1, 2012 issue of The Astrophysical Journal Letters. Credits: X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI
NASA Image of Day
May12
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New data from the Herschel Space Observatory shows that galaxies with the most powerful, active, supermassive black holes at their cores produce fewer stars than galaxies with less ones. Supermassive black holes are believed to reside in the hearts of all large galaxies. When gas falls upon these monsters, the materials are accelerated and heated around the black hole, releasing great torrents of energy. In the process, active black holes often generate colossal jets that blast out twin streams of heated matter. Inflows of gas into a galaxy also fuel the formation of new stars. In a new study of distant galaxies, Herschel helped show that star formation and black hole activity increase together, but only up to a point. Astronomers think that if an active black hole flares up too much, it starts spewing radiation that prevents raw material from coalescing into new stars. This artist concept of the local galaxy Arp 220, captured by the Hubble Space Telescope, helps illustrate the Herschel results. The bright core of the galaxy, paired with an overlaid artist’s impression of jets emanating from it, indicate that the central black hole’s activity is intensifying. As the active black hole continues to rev up, the rate of star formation will, in turn, be suppressed in the galaxy. Astronomers want to further study how star formation and black hole activity are intertwined. Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes, with important participation by NASA. Image Credit: NASA/JPL-Caltech
NASA Image of Day
Dec20
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In celebration of the twenty-first anniversary of the Hubble Space Telescope’s deployment in April 2011, astronomers at the Space Telescope Science Institute pointed Hubble’s eye to an especially photogenic group of interacting galaxies called Arp 273. The larger of the spiral galaxies, known as UGC 1810, has a disk that is tidally distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. A swath of blue jewels across the top is the combined light from clusters of intensely bright and hot young blue stars. These massive stars glow fiercely in ultraviolet light. The smaller, nearly edge-on companion shows distinct signs of intense star formation at its nucleus, perhaps triggered by the encounter with the companion galaxy. A series of uncommon spiral patterns in the large galaxy is a tell-tale sign of interaction. The large, outer arm appears partially as a ring, a feature seen when interacting galaxies actually pass through one another. This suggests that the smaller companion actually dived deep, but off-center, through UGC 1810. The inner set of spiral arms is highly warped out of the plane with one of the arms going behind the bulge and coming back out the other side. How these two spiral patterns connect is still not precisely known. The interaction was imaged on Dec. 17, 2010, with Hubble’s Wide Field Camera 3 (WFC3). This Hubble image is a composite of data taken with three separate filters on WFC3 that allow a broad range of wavelengths covering the ultraviolet, blue and red portions of the spectrum. Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
NASA Image of Day
Oct21
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This interacting pair of galaxies is included in Arp’s catalog of peculiar galaxies as number 148. Arp 148 is the staggering aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. The collision between the two parent galaxies produced a shockwave effect that first drew matter into the center and then caused it to propagate outwards in a ring. The elongated companion perpendicular to the ring suggests that Arp 148 is a unique snapshot of an ongoing collision. Infrared observations reveal a strong obscuration region that appears as a dark dust lane across the nucleus in optical light. Arp 148 is nicknamed Mayall’s object and is located in the constellation of Ursa Major, the Great Bear, approximately 500 million light-years away. This image is part of a large collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on April 24, 2008, the observatory’s 18th anniversary. Image Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
NASA Image of Day
Aug31
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NASA has established an astrophysics technology fellowship named for the woman many credit as one of the key contributors in the creation of the Hubble Space Telescope.
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