TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3435
SUBJECT: GRB 050520: TAROT optical limit
DATE:    05/05/20 11:37:42 GMT
FROM:    Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse  <atteia@ast.obs-mip.fr>

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

We imaged the entire field of GRB 050520 detected by INTEGRAL (cf. Gotz et al. GCNC 3430)
with the TAROT robotic telescope (D=25cm) located at the Calern observatory,
France. Observations started at 00:06:40s UT, 8 seconds after the GCN notice,
and 47s after the GRB. The field had an elevation of 46 degrees
above horizon at the begining of the observations.

The first two images (unfiltered) were recorded while the burst was still active.
We detect no source at the position of the X-ray afterglow seen by SWIFT
(Kennea et al. GCNC 3434), either during or after the burst. We measure the
following magnitude limits:

Image #   start time   end time   Rlim

#1        To+47s       To+62s     16.0
#2        To+69s       To+84s     16.0
#1+2      To+47s       To+84s     16.1
#3-10     To+90s       To+451s    17.2


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