[vsnet-grb-info 20519] GRB 180407A: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22615
SUBJECT: GRB 180407A: TAROT Calern observatory optical observations
DATE:    18/04/07 11:12:55 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 180407A detected by SWIFT
(trigger 823014) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 30.5s after the GRB trigger
(13.7s after the notice). The elevation of the field decreased from
53 degrees above horizon but the event occured during
the dawn. Moreover the eky was partly cloudy.
We do not detect any OT with the following limiting magnitudes:

  Tstart     Tend   LimMag
    30.5s    90.5s  R > 11.6
   104.2s   134.2s  R > 10.8
   144.3s   174.3s  R > 9.5
   184.1s   214.1s  R > 9.5
   223.9s   253.9s  R > 13.2
   263.7s   293.7s  R > 13.2
   303.8s   393.8s  R > 15.4
   403.9s   493.9s  R > 15.4
   504.4s   594.4s  R > 14.8

Magnitudes were estimated with the nearby NOMAD1 stars.