[vsnet-grb-info 15777] GRB 141022A: TAROT La Silla observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17065
SUBJECT: GRB 141022A: TAROT La Silla observatory optical observations
DATE:    14/11/13 00:35:18 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

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

We imaged the field of GRB 141022A detected by SWIFT
(trigger 616061) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 71s after the GRB trigger
(16s after the notice). The elevation of the field decreased from
24 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 with a limiting magnitude of:
t0+71s to t0+131s : Rlim = 16.4

The second image is 30.0s exposure in tracking mode:
t0+145s to t0+175s : Rlim = 17.5

Later TAROT images (until 1800s) do not show any
afterglow at Rlim = 17.5

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