Optical and Gamma Ray Space ObservationsResults of the first year of data acquired from several Earth observatories concerning the optical counterparts gamma ray bursts (GRB) are presented. From the present statistics, it seems to be obvious that typical GRB's have optical emission at the time of the burst at a level at least below 1/(F(sub gamma)/F(sub opt)) approximately equal to 1/0.5 and optical emission a few hours after the burst is lower by a factor of 10 to 200 than the simultaneous emission. Given the fact that GRB spectra are rather broad over the observed energy range of say 20 keV up to 100 MeV, the observations indicate that the broad spectral shape may not continue into the optical range. After the confirmation of the isotropic distribution of GRB's by the BATSE experiment the interpretation now tends to put the sources at cosmological distances.
IDRelationTitle19940016488WorkSunphotometer network for monitoring aerosol properties in the Brazilian Amazon19940016489WorkPredicting LANDSAT MSS endmember signatures from corresponding higher resolution TM fraction images19940016491WorkEvaluation of C-band SAR data from SAREX 1992: Tapajos study site