GCN Circular 14893

N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), A. S. Fruchter (STScI),
J. Hjorth (DARK/NBI) and K. Wiersema (U. Leicester) report:

We observed the location of GRB 130603B with HST/ACS and
WFC3/IR.  The host galaxy is clearly resolved as a disturbed spiral,
and it appears that the GRB occurred close to a spiral
arm that seems to have been tidally distorted or drawn out
by interaction with a smaller neighbour.

Our provisional analysis finds a point-source limit of F606W>27.6,
corresponding to M_V~-14.3, at the location of the GRB.  This is 
approaching a factor ~100 below what would be expected if there 
were a rising supernova comparable to SN1998bw, ruling out such an 
association for this burst.  It also rules out some part of the parameter
space of other radioactively-powered transients that have been
proposed may accompany short GRBs.

The position of the GRB lands on a region of extended emission in
the F160W (H') filter of WFC3/IR.    Another epoch scheduled for a
few weeks from now will allow a deeper search for a counterpart
through image subtraction.

We thank the STScI director and staff for rapidly expediting
these observations.