[vsnet-grb-info 5296] GRB 071025: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6987
SUBJECT: GRB 071025: ROTSE-III Detection of Optical Counterpart 
DATE:    07/10/25 04:37:51 GMT
FROM:    Eli Rykoff at U of Michigan/ROTSE  <erykoff at umich.edu>

E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), 
H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE 
collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
071025 (Swift trigger 295301, GCN 6986). The first image was at 
04:10:14.0 UT, 80.3 s after the burst (6.0 s after the GCN notice time). 
The unfiltered images are calibrated relative to USNO A2.0. We detect a 
19.2 magnitude, fading source with coordinates:

      23:40:17.19      +31:46:42.64    (J2000), with positional 
uncertainty of 1" or better

start UT    	mag     mlim(of image)
----------------------------------
04:16:27.1     19.2     18.6


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/gsb295301_3b021-030_key.jpg

Continuing observations are in progress.