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GCN Circular 8536

GRB 081121: ROTSE-III Detection of Optical Counterpart
2008-11-21T20:41:23Z (16 years ago)
Fang Yuan at ROTSE <>
F. Yuan (U Mich), W. Rujopakarn (Steward) report on behalf of the ROTSE 

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 081121 (Swift trigger 335105). The first image was at 
20:36:30.0 UT, 57.2 s after the burst (8.9 s after the GCN notice time). 
The unfiltered images are calibrated relative to USNO A2.0. We detect a 
11.6 magnitude, fading source with coordinates:

     05:57:06.1      -60:36:10.3    (J2000), with positional uncertainty 
of 1" or better

start UT    	mag     mlim(of image)
20:36:29.9     11.6     15.7 

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

A jpeg image is available at Note that the object 
marked 4 is the candidate in question.

Continuing observations are in progress.
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