Soft γ-ray repeaters (SGRs) are transient sources of high-energy photons, whose brief emissions are thought to arise from young and highly magnetized neutron stars. The exact cause of these outbursts, and the nature of the energy-loss mechanism that …
We report on Hubble Space Telescope (HST) observations of the host galaxy of GRB 971214, taken 4 months after the burst. The redshift of the proposed host galaxy at z=3.418, combined with optical and radio observations of the burst afterglow, implies …
We present spectroscopic observations of the host galaxy of GRB 980703. Several emission and absorption features are detected, making the redshift (z=0.966) completely unambiguous. This is only the third known redshift for a γ-ray burst (GRB) host. …
We report on the discovery of the radio, infrared, and optical transient coincident with an X-ray transient proposed to be the afterglow of GRB 980703. At later times when the transient has faded below detection, we see an underlying galaxy with …
We present late-time imaging and spectroscopic observations of the optical transient (OT) and host galaxy of GRB 970508. Imaging observations roughly 200 and 300 days after the burst provide unambiguous evidence for the flattening of the light curve. …
The spatial and temporal coincidence of gamma-ray burst (GRB) 980425 and supernova (SN) 1998bw has prompted speculation that there exists a subclass of GRBs produced by SNe (``S-GRBs''). A physical model motivated by radio observations lead us to …
Supernova SN 1998bw exploded in the same direction and at the same time as the gamma-ray burst GRB 980425. Here we report radio observations of this type Ic supernova, beginning 4 days after the gamma-ray burst. At its peak the radio source is the …
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 …
A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form from the …
A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form from the …