[vsnet-grb-info 5888] GRB 080330A: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7538
SUBJECT: GRB 080330A: ROTSE-III Detection of Optical Counterpart
DATE:    08/03/30 04:04:25 GMT
FROM:    Brad Schaefer at LSU  <schaefer at grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State) and T. Guver (U Istanbul) report on
behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
080330A (Swift trigger 308041). The first image was at 03:41:39.2 UT, 22.4 
s after the burst (7.2 s after the GCN notice time). The unfiltered images 
are calibrated relative to USNO A2.0. We detect a new object, not visible 
in the DSS (second epoch), with coordinates:

     11:17:04.5 +30:37:24.0 (J2000), 

with positional uncertainty of 1" or better.  This is inside the XRT error
box.  The object is roughly 17.5 magnitude, and it declined immediately
only to rise again to a peak at 16.9 mag roughly ~300 seconds after the
burst.  A jpeg image is available at
http://www.rotse.net/images/gsb308041_3b00_img.jpg

Continuing observations are in progress.