Science News: NASA/Marshall Astronomy
December 22, 1997
Perhaps no other area of astronomy has experienced such an explosive revolution in our understanding over the past year as that of gamma-ray bursts. These powerful explosions in space that are detected on a daily basis have been shown conclusively within the past 12 months to come from the most distant reaches of the Universe. Each one releases more energy in 10 seconds than our Sun will emit in its entire 10-billion-year lifetime. On January 7, 1998, Dr. Chryssa Kouveliotou, a USRA scientist at NASA/Marshall, and Sir Martin Rees, Astronomer Royal of Great Britain, will present an invited lecture to the 191st meeting of the American Astronomical Society in Washington DC, to summarize what has been an unparalleled year of discovery in the area of cosmic gamma-ray bursts.
In early 1996, an Italian-Dutch satellite, BeppoSAX, which is equipped with X-ray Cameras that have a wide field of view, obtained images of an X-ray glow immediately following a GRB. This detection opened a new era in GRB research. These images taken shortly after the burst occurred provided a very precise location in the sky which enabled optical, X-ray and radio telescopes to quickly follow up the emission region and detect the first GRB counterparts in these other wavelengths. Since then, two additional optical counterparts have been found for gamma-ray bursts, the most recent discovery coming only in the third week of December 1997.
During the invited lecture, Dr. Kouveliotou will review the main observational results of the last 7 years obtained with BATSE on the temporal, spectral, and spatial characteristics of GRBs, together with the recent optical, X-ray and radio follow-up results that have made crucial steps towards the solution of the GRB mystery.
The Wide-field Planetary Camera Image from Hubble of the burst region in the Visual band. The optical source believed to be the home of the gamma-ray burst is at the center of the photograph.
A Close-Up of the Optical Transient taken not long after the burst shows both a point-like source (the bright emission) plus the extended emission (below and to the right) from what may be the distant host-galaxy.
A later Hubble image taken in September reveals that the optical counterpart to the gamma-ray burst is still visible, indicating to astronomers that these objects are indeed from the most distant parts of the Universe.
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The 191st Meeting of the American Astronomical Society will be held at the Washington Hilton and Towers. The gamma-ray burst invited lecture will begin at 3:40 pm EST, on January 7, in the International Ballroom of the hotel. More information on the meeting can be found at the URL http://www.aas.org/meetings/aas191/program/index.html
Author: John Horack
Curator: Bryan Walls
NASA Official: John M. Horack