| First for astronomers: Observed birth of supernova |
|
| by William Atkins | |
| Friday, 23 May 2008 | |
|
Page 1 of 2   
Featured Whitepaper
5 Best Practices for Smartphone Support
The birth of the new supernova is called Supernova 2008D. The activities of the supernova event, on January 9, 2008, which lasted only about five minutes, and the lengthy aftermath during the following months, appear in the May 22, 2008 issue of the journal Nature (Soderberg, A. M. et al. Nature 453, 469–474 (2008)). See “Soderberg/Nature article.” The paper can also be found at the Arxiv.org website “An extremely luminous X-ray outburst at the birth of a supernova.” At the time of the discovery, Soderberg and Berger, both associated with Princeton’s Department of Astrophysical Sciences, were using the NASA Swift Gamma-Ray Burst satellite, sometimes just called “Swift.” What the two astronomers saw was really just the afterglow of the supernova. The dying star had already exploded within its interior. The explosion—produced from gravitational energy released by the collapse of the star’s interior—created an expanding debris shell (the afterglow). This amount of released energy was sufficient to blow the star to smithereens, as the surface of the star was heated to extremely hot temperatures. Material was shot out in all direction, flying off at a small percentage of the speed of light—at about 6,210 miles per second (10,000 kilometers per second), which is about 3.3% the speed of light. Ultraviolet and x-ray radiation was shot out, too, along with neutrinos and gravitational waves. Astronomers here on Earth saw an initially bright wave front, when using a telescope set to observe in the x-ray portion of the electromagnetic spectrum, but found that it soon faded slowly away. The initial blast seen by the two Princeton astronomers was estimated to be about 100 billion times brighter than our Sun. And, of course, we humans only saw the supernova as a delayed action because it takes radiation (light) a certain amount of time to reach Earth, depending on its distance away from us. The blast by the dying star as it produced Supernova 2008D actually happened about 84 million years ago, if we assume the dying star was located at about 84 million light-years away from us. We see it in "real-time" from our point of view, not the point of view of the exploding star, which has long since died. The radiation expelled from the star has been traveling at the speed of light for all of these years, and just got to us last January 9th. Afterwards, Soderberg stated, “We caught the whole thing on tape, so to speak. I truly won the astronomy lottery. A star in the galaxy exploded right in front of my eyes.” [The New York Times: “Scientists See Supernova in Action”] It was, indeed, the birth of a supernova. Soderberg stated, “It was a baby supernova in that sense. Here was an object brand new. At first we didn’t recognize it.” [The New York Times] So, astronomers knew what to look for when observing the initial start of a supernova. They just had never been able to actually see one in real time. Until now, that is. Please read on. |
| < Next story in category | Previous story in the category > |
|---|
