Abstract
We report on the results of optical follow-up observations of the counterpart of the gamma-ray burst GRB 970508, starting 7 hr after the event. Multicolor U-, B-, V-, R-c-, and I-c-band observations were obtained during the first three consecutive nights. The counterpart was monitored regularly in R-c, until similar to 4 months after the burst. The light curve after the maximum follows a decline that can be fitted with a power law with exponent alpha = -1.141 +/- 0.014. Deviations from a smooth power-law decay are moderate (rms = 0.15 mag). We find no flattening of the light curve at late times. The optical afterglow fluence is a significant fraction, similar to 5%, of the GRB fluence. The optical energy distribution can be well represented by a power law, the slope of which changed at the time of the maximum (the spectrum became redder).
Original language | English |
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Pages (from-to) | L13 |
Number of pages | 1 |
Journal | Astrophysical Journal |
Volume | 497 |
Issue number | 1 PART II |
Publication status | Published - 1998 |
ASJC Scopus subject areas
- Space and Planetary Science