<p> NASA's Swift satellite has discovered one of the youngest-known supernova remnants - believed to be less than 2,500 years old - in our Milky Way galaxy.<br /><br />The new object, discovered while performing an extensive X-ray survey of our galaxy's central regions, has been designated G306.3–0.9 after the coordinates of its sky position, NASA said in a statement.<br /><br />"Astronomers have previously catalogued more than 300 supernova remnants in the galaxy," said lead scientist Mark Reynolds, researcher at the University of Michigan in Ann Arbor.<br /><br />"Our analysis indicates that G306.3–0.9 is likely less than 2,500 years old, making it one of the 20 youngest remnants identified," Reynolds said.<br /><br />Astronomers estimate that a supernova explosion occurs once or twice a century in the Milky Way. The expanding blast wave and hot stellar debris slowly dissipate over hundreds of thousands of years, eventually mixing with and becoming indistinguishable from interstellar gas.<br /><br />On February 22, 2011, Swift imaged a survey field near the southern border of the constellation Centaurus. Although nothing unusual appeared in the ultraviolet exposure, the X-ray image revealed an extended, semi-circular source reminiscent of a supernova remnant.<br /><br />A search of archival data revealed counterparts in Spitzer infrared imagery and in radio data from the Molonglo Observatory Synthesis Telescope in Australia.</p>.<p><br />To further investigate the object, the team followed up with an 83-minute exposure using NASA's Chandra X-ray Observatory and additional radio observations from the Australia Telescope Compact Array (ATCA), located near the town of Narrabri in New South Wales.</p>.<p><br />Using an estimated distance of 26,000 light-years for G306.3–0.9, the scientists determined that the explosion's shock wave is racing through space at about 2.4 million km/h.<br /><br />The Chandra observations reveal the presence of iron, neon, silicon and sulfur at temperatures exceeding 28 million C, a reminder not only of the energies involved but of the role supernovae play in seeding the galaxy with heavy elements produced in the hearts of massive stars.<br /><br />"We don't yet have enough information to determine what type of supernova this was and therefore what type of star exploded, but we've planned a further Chandra observation to improve the picture," said co-author Jamie Kennea, a researcher at the Swift Mission Operations Center.</p>.<p><br />The findings will be published in The Astrophysical Journal. </p>
<p> NASA's Swift satellite has discovered one of the youngest-known supernova remnants - believed to be less than 2,500 years old - in our Milky Way galaxy.<br /><br />The new object, discovered while performing an extensive X-ray survey of our galaxy's central regions, has been designated G306.3–0.9 after the coordinates of its sky position, NASA said in a statement.<br /><br />"Astronomers have previously catalogued more than 300 supernova remnants in the galaxy," said lead scientist Mark Reynolds, researcher at the University of Michigan in Ann Arbor.<br /><br />"Our analysis indicates that G306.3–0.9 is likely less than 2,500 years old, making it one of the 20 youngest remnants identified," Reynolds said.<br /><br />Astronomers estimate that a supernova explosion occurs once or twice a century in the Milky Way. The expanding blast wave and hot stellar debris slowly dissipate over hundreds of thousands of years, eventually mixing with and becoming indistinguishable from interstellar gas.<br /><br />On February 22, 2011, Swift imaged a survey field near the southern border of the constellation Centaurus. Although nothing unusual appeared in the ultraviolet exposure, the X-ray image revealed an extended, semi-circular source reminiscent of a supernova remnant.<br /><br />A search of archival data revealed counterparts in Spitzer infrared imagery and in radio data from the Molonglo Observatory Synthesis Telescope in Australia.</p>.<p><br />To further investigate the object, the team followed up with an 83-minute exposure using NASA's Chandra X-ray Observatory and additional radio observations from the Australia Telescope Compact Array (ATCA), located near the town of Narrabri in New South Wales.</p>.<p><br />Using an estimated distance of 26,000 light-years for G306.3–0.9, the scientists determined that the explosion's shock wave is racing through space at about 2.4 million km/h.<br /><br />The Chandra observations reveal the presence of iron, neon, silicon and sulfur at temperatures exceeding 28 million C, a reminder not only of the energies involved but of the role supernovae play in seeding the galaxy with heavy elements produced in the hearts of massive stars.<br /><br />"We don't yet have enough information to determine what type of supernova this was and therefore what type of star exploded, but we've planned a further Chandra observation to improve the picture," said co-author Jamie Kennea, a researcher at the Swift Mission Operations Center.</p>.<p><br />The findings will be published in The Astrophysical Journal. </p>