Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

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.
Looking for U.S. government information and services? Visit