[vsnet-grb-info 2120] GRB 050910a: TAROT early optical limits

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3959
SUBJECT: GRB 050910a: TAROT early optical limits
DATE:    05/09/10 04:54:37 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

Klotz, A. (CESR-OMP), Boer M. (OHP), and Atteia, J.L. (LAT-OMP) report:

We imaged the entire field (1 x1 deg) of GRB 050910a detected by HETE
(Trigger #3924) with the TAROT robotic telescope (D=25cm) located at the
Calern observatory, France. Observations started 8 seconds after the
GCN notice (and 25 s after the GRB). The field had an elevation of
46 degrees above horizon at the begining of the observations.
All images were taken withour any filter.

First six images taken between 2005-09-10T01:16:44.86 (GRB +  25s)
and 2005-09-10T01:19:31.50 (GRB + 192s) were co-added. The afterglow
is not detected. The limiting magnitude is estimated to be
R=18.9 +/- 0.1 comparing with the USNO-B1 nearby stars.

A second set of images taken between 2005-09-10T01:20:00.51
(GRB + 221s) and 2005-09-10T02:05:10.63 (GRB + 2931s) we co added.
The limiting magnitude is estimated to be
R=19.3 +/- 0.1 comparing with the USNO-B1 nearby stars.

This notice can be cited.