T
telfrow
Guest
<i>Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence, sloppily gorging on material falling into them while somehow propelling other material away at great speeds.<br /><br />These black holes are born in massive star explosions. An initial blast obliterates the star. Yet the chaotic black hole activity appears to re-energize the explosion again and again over the course of several minutes. This is a dramatically different view of star death, one that entails multiple explosive outbursts and not just a single bang, as previously thought.<br /><br />"Stars are exploding two, three and sometimes four times in the first minutes following the initial explosion," said David Burrows, professor of astronomy and lead author on a paper appearing online today (Aug. 18, 2005) on Science Express and in the Sept. 9 issue of the journal Science. "First comes a blast of gamma rays followed by intense pulses of X-rays. The energies involved are much greater than anyone expected."<br /><br />Scientists have seen this phenomenon in nearly half of the longer gamma-ray bursts detected by Swift so far. These gamma-ray bursts, the most powerful explosions known, are harbingers of a type of massive star explosion called a hypernova, bigger than a supernova. With the Swift satellite, scientists finally are able to see gamma-ray bursts within minutes after the trigger, instead of hours or days, and are now privy to newborn-black-hole activity. Until this latest Swift discovery, scientists had assumed a simple scenario of a single explosion followed by a graceful afterglow of the dying embers.<br /><br />"The newly formed black hole immediately gets to work," said Peter Meszaros, who holds the Eberly family chair in the Eberly College of Science and is head of the Swift theory team. "We aren't clear on the details yet, but it appears to be messy. Matter is falling into the black hole, which releases a great amount of en</i> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>