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<b>Swift Mission Sees Its First Gamma Ray Bursts</b><br /><br />LINK<br /><br />NASA's Swift space telescope, launched in November 2004, has opened its eyes to the most powerful explosions in the universe. In less than a month, it has already pinpointed 9 gamma ray bursts - several more than astronomers expected.<br /><br />The first gamma ray burst (GRB) came into Swift's field of view on 17 December, just a few days after controllers first turned on its instruments. Then, on 19 December, the telescope caught three more.<br /><br />The purpose of Swift's mission is to understand what GRBs are, says David N. Burrows, lead scientist for Swift's X-Ray Telescope, at Penn State University, US. "They're very enigmatic things," he says. "We hope to understand what's causing them and how these things are interacting with the medium around them. And we hope to find clues to the evolution of the early universe." <br /><br />Scientists suspect the GRBs indicate the explosive birth of black holes, but there are different types of burst and it is hoped that Swift's data will help to discern all the possible causes.<br /><br />The NASA-led Swift mission launched from Cape Canaveral Air Force Station in Florida, US, on 27 November 2004, carrying the most sensitive gamma ray detectors ever flown. The telescope's initial observations, revealed on Wednesday, were carried out primarily to prove that its systems were working well.<br /><br />Reaction times<br />A key aspect of the $250 million mission is to measure the X-ray glow that lingers long after the bursts themselves. GRBs can last as little as just a few seconds or even milliseconds, but Swift's first big opportunity to study an afterglow arrived on 23 December when it spotted a GRB classified as a long burst, lasting over a minute.<br /><br />Four-and-a-half hours after spotting the GRB, the satellite swivelled its X-ray telescope around to measure the afterglow. Pr