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GCN Circular 7538

GRB 080330A: ROTSE-III Detection of Optical Counterpart
2008-03-30T04:04:25Z (16 years ago)
Brad Schaefer at LSU <>
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

Continuing observations are in progress.
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