[vsnet-grb-info 11741] GRB 120327A: TAROT La Silla observatory optical decay

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13132
SUBJECT: GRB 120327A: TAROT La Silla observatory optical decay
DATE:    12/03/27 07:04:56 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:

We continue observations of GRB 120327A (trigger 518731)
with the TAROT robotic telescope (D=25cm) located at the
European Southern Observatory, La Silla observatory, Chile.

An optical decay alpha=1.3 (+/- 0.3) is deduced from the
following observations:

No filter:
start  end     Rmag  dmag filter
(sec)  (sec)
1944.2 2234.6  16.96 0.17 CR
2387.2 3159.2  17.31 0.19 CR
3169.5 3938.0  17.81 0.09 CR
4156.0 4916.2  18.03 0.17 CR
4926.5 6102.7  18.84 0.13 CR

R filter:
start   end     Rmag  dmag filter
(sec)   (sec)
2767.6  3539.5  17.65 0.09 R
3948.0  4716.3  18.34 0.32 R
5116.5  7072.8  18.56 0.17 R
7472.9 10018.6  18.84 0.09 R

Photometry is relative to the star NOMAD1 0605-0398765:
(ra,dec) J2000 = (246.8438328,-29.4187269) R=14.930.
Magnitudes are not corrected for galactic dust extinction.

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