TITLE:   GCN CIRCULAR
NUMBER:  17387
SUBJECT: GRB 150203A: TAROT La Silla observatory optical observations
DATE:    15/02/03 10:41:40 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@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 150203A detected by SWIFT
(trigger 629578) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 37.1s after the GRB trigger
(13.6s after the notice). The elevation of the field decreased from
45 degrees above horizon and weather conditions
were good but the field of view is located at low
galactic latitude (extinction estimated > 14 magnitudes
in the R band).

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+37.1s to t0+97.1s : Rlim = 15.8

The second image is 90.0s exposure in tracking mode:
t0+391s to t0+481s : Rlim = 16.4

We co-added a series of exposures:
t0+391s to t0+1203s : Rlim = 17.0

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

N.B. Galactic coordinates are lon=204.7072 lat= -0.7535