[vsnet-grb-info 5255] GRB 071020A: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6948
SUBJECT: GRB 071020A: ROTSE-III Detection of Optical Counterpart
DATE:    07/10/20 07:17:21 GMT
FROM:    Brad Schaefer at LSU  <schaefer at grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State), T.A. McKay (U Mich), F. Yuan (U Mich), 
report on behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
071020A (Swift trigger 294835). The first image was at 07:02:52.5 UT, 25.6 
s after the burst (9.5 s after the GCN notice time). The unfiltered images 
are calibrated relative to USNO A2.0. We detect a 13.6 magnitude, fading 
source with coordinates:

     07:58:39.9      +32:51:41.4    (J2000), with positional uncertainty 
of 1" or better

start UT    	mag     mlim(of image)
----------------------------------
07:02:52.9     13.6     16.4 


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

A jpeg image is available at 
http://www.rotse.net/images/gsb294835_3b00_img.jpg

Continuing observations are in progress.