[vsnet-grb-info 3670] GRB 060904A: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5504
SUBJECT: GRB 060904A: ROTSE-III Detection of Optical Counterpart 
DATE:    06/09/04 02:45:01 GMT
FROM:    Eli Rykoff at U of Michigan/ROTSE  <erykoff at umich.edu>

E.S. Rykoff (U Mich), W. Rujopakarn (U Mich), F. Yuan (U Mich), report 
on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 060904A (Swift trigger 228006). The first image was at 
02:31:22.4 UT, 18.5 s after the burst (5.3 s after the GCN notice time). 
The unfiltered images are calibrated relative to USNO A2.0. We detect a 
17.3 magnitude, brightening source with coordinates:

      03:52:50.52      -00:43:30.85    (J2000)

start UT    	mag     mlim(of image)
----------------------------------
02:31:22.4     17.3     18.1

A jpeg image is available at 
http://www.rotse.net/images/gsb228006_3c011-020_key.jpg

Continuing observations are in progress.