A GRB Host?
Where do
gamma-ray bursts (GRBs) originate? The most powerful
explosions in the universe have
recently been located with record accuracy.
But do GRBs occur in galaxies or out alone in deep space?
This picture
taken with the
Hubble
Space Telescope of the field surrounding
GRB 970228 might provide a clue.
It appears to show an extended structure to the lower right of the
GRB, which is identified with an arrow.
Many astronomers speculate that this extended structure is a
distant galaxy, as its colors and subsequent
steady emission indicate. Other astronomers worry that the extended
emission is variable and so cannot be a galaxy. Astronomers hoping for
more cases to study were rewarded just last Monday with a new, well-located event:
GRB 970616. The location of this burst was determined by an unprecedented
collaboration involving the tandem use of NASA satellites
Compton,
Ulysses and
Rossi.