Er vi truet af gammastråler?   This artist's impression illustrates how a gamma-ray burst can flare dramatically over a short time period. Gamma-ray bursts can occur as often as several time a day but they last for no longer than a couple of minutes. There is no way to predict when or where they will next occur. ESA missions such as XMM-Newton, INTEGRAL and Ulysses study these mysterious, powerful bursts. Copyright: ESA 2002. Illustration by Medialab   Detecting the Universe's hot spots. Sammenhæng mellem GRB'er og eksploderende stjerner     Image of the field around the gamma-ray burst (971214), obtained with the Hubble Space Telescope about four months after the burst, well after the afterglow has faded away. The extremely faint and distant galaxy (marked with an arrow) is the host galaxy of the gamma-ray burst. It was discovered earlier using the Keck 10-metre telescope. Release date: 17 September 2003