Gamma-ray bursts — the current status

The field of gamma ray burst astronomy is reviewed with emphasis on the results obtained since 1978 by numerous spacecraft experiments. Burst energy spectra are now known to display complex and rapidly varying shapes; however, the detection of line emission poses both experimental and theoretical problems. The log N-log S curves, when properly corrected for instrumental effects, are substantially in agreement at high intensities, although the shape of the curves is inconsistent with the observed spatial distribution of the bursts. Precise localizations using the method of arrival time analysis between widely separated spacecraft have given small error boxes which have in many cases been searched down to magnitude 23.5 and beyond. The results of these searches, as well as those of archibal and real-time optical searches, are reviewed.