[vsnet-grb-info 2282] GRB 051021: ROTSE-III Confirmation of Optical Counterpart

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4121
SUBJECT: GRB 051021: ROTSE-III Confirmation of Optical Counterpart
DATE:    05/10/21 17:37:42 GMT
FROM:    Heather Swan at U.of Michigan/ROTSE  <hflewell at umich.edu>

H. Swan (U Mich), T.A. McKay (U Mich), D.A. Smith (Guilford), B. 
Schaefer (Louisiana State), E.S. Rykoff (U Mich), F. Yuan (U Mich), 
report on behalf of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded 
to GRB 051021 (HETE trigger 3947). The first image was at 13:22:28.4 UT, 
31.8 s after the burst (6.6 s after the GCN notice time). The unfiltered 
images are calibrated relative to USNO A2.0. We confirm the presence of 
the source detected by Fox et. al. GCN # 4120.  We observe the source to 
rise to 16.9 magnitude, at about 180 seconds, and then fade by half a 
magnitude over a period of 150 seconds.

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

Continuing observations are in progress.

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