Stunning X-ray Image Shows Pulsar at Center of Sup

[KTMCDO]

<title>Stunning X-ray Image Shows Pulsar at Center of Sup KENT MCDONALD KTMCDO ktmcdo@netzero.net</title>
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By SPACE.com staff<br>
posted: 09:17 am ET<br>
23 October 2001<br>
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A team of astronomers using the Chandra X-ray Observatory has found what appears to be a pulsar at the center of the exploded remains of a 1,600-year-old supernova. <br>
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Pulsars, first discovered in 1967, are known to be rapidly rotating neutron stars, formed in supernova explosions. They emit regular bursts or pulses of radio waves, X-rays and optical light. A neutron star is the incredibly dense remains of an aged star. <br>
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Astronomers know that pulsars are formed in supernova explosions, but they currently don't know what types of massive stars must die in order for a pulsar to be born. The new image provides a much closer link between pulsars and the massive stars from which they form, the researchers said.<br>
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"For the first time, we have an oxygen-rich supernova remnant close enough for detailed study, with almost incontrovertible evidence for the existence of an associated pulsar," John P. Hughes of Rutgers University. "Based on the pattern of elements now revealed by Chandra throughout this remnant, we will be able to ascertain the mass and composition of the star that gave rise to what we now see. This will allow us to make a much closer connection between pulsars and the massive stars from which they formed."<br>
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Supernovae are of great interest to astronomers because they are one of the primary sources of the heavy elements necessary to form planets and people. Supernovae are somewhat rare, occurring only once every 50 years or so in a galaxy like our Milky Way.<br>
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Located in the Southern Hemisphere in the constellation Centaurus, the supernova remnant, officially known as G292.0+1.8, shows a rapidly expanding shell of gas 36 light-years across surrounding the apparent pulsar. It is one of three known oxygen-rich supernovae in our galaxy and is among the 10 brightest supernova remnants known.<br>
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Scattered throughout the image are bluish knots of emission containing material that is highly enriched in newly-created oxygen, neon, and magnesium produced deep within the original star and ejected by the supernova explosion. <br>
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Elsewhere in the image one can trace whitish colored regions (like the thin, nearly horizontal filaments just above the purple nebula) and yellow regions (mainly around the periphery, best seen toward the upper right). This material is of a more standard composition, without the enrichment seen elsewhere, and represents either the pre-existing surrounding matter or the outer layers of the star itself, lost at an earlier time before the star exploded as a supernova.<br>
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Details of the observations are published in the Oct. 1 issue of Astrophysical Journal Letters.<br>
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