[vsnet-grb-info 18704] GRB 161105A: TAROT La Silla observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20152
SUBJECT: GRB 161105A: TAROT La Silla observatory optical observations
DATE:    16/11/08 22:25:29 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 161105A detected by SWIFT
(trigger 720697) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 27.4s after the GRB trigger
(14.8s after the notice). The elevation of the field increased from
31 degrees above horizon and weather conditions
were excellent.

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 XRT error box provided by
Page et al. GCNC 20131) with a limiting magnitude of:

t0+27.4s to t0+87.4s : Rlim = 16.5

Due to technical problems the second image was taken only
743 seconds after the GRB:

t0+743.2s to t0+833.2s : Rlim = 19.8

No more candidate were found in the next images taken
until 2000 seconds after the GRB at the same limiting
magnitude.

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