[vsnet-grb-info 14071] GRB 131026A: TAROT La Silla observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15385
SUBJECT: GRB 131026A: TAROT La Silla observatory optical observations
DATE:    13/10/26 07:20:49 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP), Gendre B.,
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 131026A detected by SWIFT
(trigger 575905) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 86.9s after the GRB trigger
(13.7s after the notice). The elevation of the field decreased from
12 degrees above horizon and weather conditions
were good.

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 with a limiting magnitude of:
t0+86.9s to t0+146.9s : Rlim = 16.8

The second image is 30.0s exposure in tracking mode:
t0+160.5s to t0+190.5s : Rlim = 17.4

We co-added a series of exposures:
t0+160.5s to t0+451.9s : Rlim = 18.9

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=125.5580 lat=-30.3300
and the galactic extinction in R band is about 0.2 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.