[vsnet-grb-info 3795] GRB 060927A: ROTSE-III Detection of Optical Counterpart

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5629
SUBJECT: GRB 060927A: ROTSE-III Detection of Optical Counterpart
DATE:    06/09/27 15:12:21 GMT
FROM:    Brad Schaefer at LSU  <schaefer at grb.phys.lsu.edu>

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

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to
GRB 060927A (Swift trigger 231362). The first image was at 14:07:51.8 UT,
16.5 s after the burst (4.8 s after the GCN notice time). The unfiltered
images are calibrated relative to USNO A2.0. We detect a fading source
with coordinates:

     21:58:11.93      +05:21:50.32    (J2000)

start UT    	mag     
-----------------------
14:07:51.8     16.5
14:08:05.8     17.1   


This source faded fast over the next minute and was well seen in only
our first three images.  This source is not visible in DSS (second epoch),
2MASS, or the MPChecker database.

Continuing observations are in progress.