[vsnet-grb-info 12200] GRB 120805A: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13589
SUBJECT: GRB 120805A: TAROT Calern observatory optical observations
DATE:    12/08/05 22:01:24 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 120805A detected by SWIFT
(trigger 530031) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 77.2s after the GRB trigger
(19.3s after the notice). The elevation of the field decreased from
20 degrees above horizon and weather conditions
were moonlight.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT in the BAT error box
with a limiting magnitude of:
t0+77.2s to t0+137.2s : R > 15.9

The second image is 30.0s exposure in tracking mode:
t0+152.6s to t0+182.6s : R > 16.2

We co-added a series of exposures:
t0+152.6s to t0+851s : R > 17.4

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

N.B. Galactic coordinates are lon=353.7578 lat=+58.9832
and the galactic extinction in R band is about 0.1 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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