[AAVSO-HEN] GRB 070810: ROTSE-III Detection of Optical Counterpart

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  6734
SUBJECT: GRB 070810: ROTSE-III Detection of Optical Counterpart
DATE:    07/08/10 03:12:03 GMT
FROM:    Heather Swan at U.of Michigan/ROTSE  <hflewell at umich.edu>

H. Swan (U Mich), B. E. Schaefer (Louisiana State), E.S. Rykoff (U 
Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
070810 (Swift trigger 287364). The first image was at 02:34:02.5 UT, 
1330.5 s after the burst. The unfiltered images are calibrated relative 
to USNO A2.0. We detect a 16.7 magnitude, fading source with coordinates:

      12:39:51.48      +10:45:00.90    (J2000).

The source is blended with a nearby USNO star visible in the DSS, and 
thus our initial positional uncertainty is ~3".

start UT    	mag     mlim(of image)
----------------------------------
02:29:53.4     16.7     18.5


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/gsb0174_3b01_img.jpg

Continuing observations are in progress.