[vsnet-grb-info 19921] GRB 171013A: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22008
SUBJECT: GRB 171013A: TAROT Calern observatory optical observations
DATE:    17/10/13 09:35:10 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

Klotz A., Noysena.K., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Eymar, L. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 171013A detected by SWIFT
(trigger 778435) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 33.3s after the GRB trigger
(12.8s after the notice). The elevation of the field increased
from 50 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+33.3s to t0+93.3s : Rlim = 16.8

The second image is 30.0s exposure in tracking mode:
t0+106.1s to t0+136.1s : Rlim = 17.8

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

N.B. Galactic latitude is +1.2 deg and the galactic
extinction in R band is higher than 2 magnitudes
from D. Schlegel et al. 1998ApJ...500..525S.