[vsnet-grb-info 13550] GRB 130612A: TAROT La Silla observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14883
SUBJECT: GRB 130612A: TAROT La Silla observatory optical observations
DATE:    13/06/12 08:53:25 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

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

We imaged the field of GRB 130612A detected by SWIFT
(trigger 557976) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 34.4s after the GRB trigger
(14.5s after the notice). The elevation of the field increased from
40 degrees above horizon and weather conditions
were excellents.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We detect the OT detected by Racusin et al. (GCNC 14874),
Melandri et al. (GCNC 14875). Photometry is done using
NOMAD-1 1067-0303513 (R.A.=259.7905194 Dec=+16.7139250
R=16.9) as reference star.

At the start of the trail t0+34.4s R=16.9
At the end of the trail   t0+94.4s R=17.5

Next images are acquired in tracking mode.
The afterglow is visible more than 30
minutes after the burst. One of the last
measurement is:

 From t0+1466s to t0+2113s  R=19.9

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

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