TITLE:   GCN CIRCULAR
NUMBER:  7935
SUBJECT: GRB 080703A: ROTSE-III Detection of Optical Counterpart 
DATE:    08/07/03 19:06:08 GMT
FROM:    Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>

E.S. Rykoff (UCSB), B. E. Schaefer (Louisiana State), report on behalf 
of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded 
to GRB 080703A (Swift trigger 315819). The first image was at 19:00:45.1 
UT, 31.5 s after the burst (11.1 s after the GCN notice time). The 
unfiltered images are calibrated relative to USNO A2.0. We detect a 14.7 
magnitude, steady source with coordinates:

      06:47:12.7      -63:13:08.6    (J2000), with positional 
uncertainty of 1" or better

start UT    	mag     mlim(of image)
----------------------------------
19:00:45.1     14.7     15.9


This source is not visible in DSS (second epoch), 2MASS or the MPChecker 
database.

A jpeg image is available at 
http://www.rotse.net/images/gsb315819_3a00_img.jpg Note that the object 
marked 18 is the candidate in question.

Continuing observations are in progress.