[vsnet-grb-info 19313] GRB 170409A: TAROT Reunion observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21008
SUBJECT: GRB 170409A: TAROT Reunion observatory optical observations
DATE:    17/04/10 16:38:25 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.)
Peyrot A., Teng J.P. (Les Makes Observatory, France),
Thierry P. (Auragne Observatory, France),
Klotz A.N.O. (Guitalens Observatory, France)
report:

We imaged the field of GRB 170409A detected by Fermi LAT and GBM
(trigger 513398525/170409112) with the TAROT robotic telescope (D=18cm)
located at the Reunion observatory, France.

The GRB is located at 34 degrees from the sun and is
observable only in the dawn light in the morning.

The observations started 0.95 day after the GRB trigger.
We stacked 13 images of 120s and examined a field of view of 0.2
degree (radius) around the position provided by
Longo et al. (GCNC 21004). We do not see any new source
at the limiting magnitude of:

t0+0.95d to t0+0.96h : Rlim=17.0 +/- 0.2

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