[vsnet-grb-info 6445] GRB 080804: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8056
SUBJECT: GRB 080804: ROTSE-III Detection of Optical Counterpart
DATE:    08/08/04 23:28:02 GMT
FROM:    Wiphu Rujopakarn at U AZ/Steward  <wiphu at as.arizona.edu>

W. Rujopakarn (Steward), E.S. Rykoff (UCSB) report on behalf of the ROTSE
collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to GRB 080804 (Swift trigger 319016). The first image was at
23:20:34.3 UT, 19.6 s after the burst (6.3 s after the GCN notice time).
The unfiltered images are calibrated relative to USNO A2.0. We detect a
17.2 magnitude, brightening source with coordinates:

     21:54:40.1      -53:11:03.8    (J2000), with positional uncertainty
of 1" or better

start UT    	mag     mlim(of image)
----------------------------------
23:20:50.2     17.2     16.9


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/gsb319016_3c01_img.jpg Note that the object
marked 38 is the candidate in question.

Continuing observations are in progress.