[vsnet-grb-info 4175] GRB 061218: TAROT La Silla observatory early optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5980
SUBJECT: GRB 061218: TAROT La Silla observatory early optical observations
DATE:    06/12/25 01:46:47 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:

We solve technichal problems that prevent to
acces to the first trailed image of GRB 061218
obtained with TAROT located at the European Southern
Observatory, La Silla observatory, Chile.

The observations started 61s after the GRB trigger
(4s after the notice). The trailed image allows to
follow continuously variable sources during the 60s
integration time (see technichal description in
Klotz et al., 2006, A&A 451, L39). We analyzed
the GRB error box provided by Sato et al. GCN
Circ. 5940. No variable object is detected.
To summarize:

t0+ 61.0s to t0+121.0s : R > 15.8
t0+126.5s to t0+156.5s : R > 17.4 (CGNC 5943)
t0+162.3s to t0+192.3s : R > 17.4 (CGNC 5943)
t0+126.5s to t0+510.6s : R > 18.0 (CGNC 5943)

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

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