"Observations of X-ray Counterparts to Gamma-ray Bursts in RXTE's All-Sky Monitor"

g X-ray sources: two optical counterparts (GRB 970228 and GRB 970508), and a radio counterpart (GRB 970508) (IAUC 6572, 6584, and many others). These results are finally enabling theorists to test their predictions. Wijers, Rees, & M'esz'aros (1997) conclude that the afterglow from GRB 970228 is consistent with the expected emission from an expanding relativistic fireball at cosmological distances. Waxman (1997) reaches the same conclusion for GRB 970508. Indeed, optical observations of 970508 showed absorption lines at z = 0:83 and no Lyman-ff forest, strong evidence for a cosmological origin at 0:83 ! z ! 2:3 (Metzger et al. 1997). These successes were made possible by the rapid (a few hours) reduction of the X-ray data and quick followup ( 1 day) by both space- and ground-based observatories. Further progress in all areas of GRB investigation now depend