TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3366
SUBJECT: GRB050505: Optical Afterglow Candidate
DATE:    05/05/06 07:25:58 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. Bradley Cenko, Chuck Steidel, Naveen Reddy, and Derek B. Fox report
on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

We have imaged the field of GRB050505 (GCN 3360) with the Keck Low
Resolution Imaging Spectrometer (LRIS) mounted on the 10-m Keck I
Telescope.  Observations in imaging mode consisted of 2 x 300 s
simultaneous exposures in the g' and I filters.  The mean epoch of our
observations is approximately 5:45 UT 6 May 2005 (~ 6.1 hours after the
burst).

In the XRT error circle reported in GCN 3365, we find one bright source,
with coordinates (J2000.0):

	RA: 09:27:03.3
	Dec: +30:16:23.7

We tentatively identify this source as the afterglow of GRB050505.