[vsnet-grb-info 3974] GRB 061109: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5791
SUBJECT: GRB 061109: TAROT Calern observatory optical observations
DATE:    06/11/09 01:37:27 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

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

We imaged the field of GRB 061109 detected by SWIFT
(trigger 237821) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France. When this
message is written, this trigger is only suspected
to be a GRB (Falcone et al. GCNC 5790).

The observations started 59.1s after the GRB trigger
(45s after the notice). The elevation of the field decreased from
from 2 degrees above horizon with a lot of humidity (86%).

The date of trigger : t0 = 2006-11-09T00:30:19.584

The first image is 30.0s exposure in tracking mode:
We do not detect any OT with a limiting magnitude of:
t0+59.1s to t0+89.1s : R > 14.1

The second image is 30.0s exposure in tracking mode:
t0+95.4s to t0+125.4s : R > 14.1

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon= 68.2186 lat=-11.8641
and the galactic extinction in R band is 0.6 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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