[vsnet-grb-info 5348] GRB 071101: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7035
SUBJECT: GRB 071101: TAROT Calern observatory optical observations
DATE:    07/11/02 07:27:06 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 071101 detected by SWIFT
(trigger 295779) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 39.4s after the GRB trigger
(7.1s after the notice). The elevation of the field increased from
from 36 degrees above horizon and weather conditions
were good. Images were acquired with no filter.

The date of trigger : t0 = 2007-11-01T17:53:46.752

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 at the XRT location defined
by Pagani et al. GCN Circ. 7034) with a limiting magnitude of:
t0+39.4s to t0+99.4s : R > 16.3

The second image is 30.0s exposure in tracking mode:
t0+106.4s to t0+136.4s : R > 17.5

We co-added a series of exposures:
t0+106.4s to t0+393.6s : R > 18.4

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

N.B. Galactic coordinates are lon=138.4726 lat= +3.9459
and the galactic extinction in R band is about 4.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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