Revolutions often start with a bang. Such a blast may have been delivered by a
supernova that may force
scientists to rethink how stars die. For now, observers have a classic situation - evidence that points in different directions and dares anyone to find a single answer.The following is a snippet of the article of October 21, 1998, which I found on this, http://science.msfc.nasa.gov/newhome/headlines/ast21oct98_1.htm and there are many images to be seen here.
All of this may lead to a revolution in our thinking about how
core-collapse supernovae are produced, wrote Dr. Eddie Baron of the University of Oklahoma in the Oct. 15 issue of the prestigious science journal, Nature. Questions to be answered include what causes ordinary supernovae, is there a limit in their energy release, and when does core collapse cause a
gamma-
ray burst?
Baron was commenting on three Nature papers describing, as the first paper is titled, An unusual supernova in the error box of the gamma-ray burst of 25 April 1998. The lead author is Titus J. Galama, a graduate student at the Astronomical Institute at the University of Amsterdam, The Netherlands. Among his many co-authors are Dr. Jan van Paradijs of the University of Amsterdam and the University of Alabama in Huntsville (UAH), Drs. Chryssa Kouveliotou, Craig Robinson and Thomas Koshut of the Universities Space Research Association at Marshall Space Flight Center, and Dr. Marc Kippen, also of UAH.
The excitement started about 140 million years ago, near the end of the Jurassic period when dinosaurs were in their prime, but the news just arrived on April 25, 1998, when instruments aboard several spacecraft recorded a strong flash of gamma radiation. Optical astronomers pointing powerful ground-based telescopes to the direction of the X-rays from the gamma-ray burst discovered a supernova in a distant galaxy. Scientists estimate that the blast, perhaps 10 times greater than an ordinary supernova, collapsed the core of the dying star into a black hole. At the same time, it slammed enough matter - mostly radioactive nickel 56 weighing 70 percent as much as our sun - outward to create a shock wave of gamma radiation.
This raises the possibility that hypernovae might be a significant cause of gamma-ray
bursts. Scientists have puzzled over gamma-ray bursts since the late 1960's when they were discovered. Not until the last couple of years, though, were they able to conclude that the bursts were from cosmological distances, that is, from far outside our own galaxy.