[vsnet-grb-info 13442] GRB 130605A: TAROT La Silla observatory optical detection of the afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14775
SUBJECT: GRB 130605A: TAROT La Silla observatory optical detection of the afterglow
DATE:    13/06/06 00:39:55 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 130605A detected by SWIFT
(trigger 557508) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 32.7s after the GRB trigger
(12.8s after the notice). The elevation of the field decreased from
51 degrees above horizon and weather conditions
were excellents.

We detect a new fading source in the error box given by SWIFT
at the following position (+/- 3 arcsec):

RA(J2000.0)  = 08h 58m 08.53s
DEC(J2000.0) = +33d 27' 40.1"

OT was R = 15.1 at  121s after GRB.
OT was R = 18.4 at 1705s after GRB.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
The afterglow is seen but the trail is overlaped
by another star and will be analyzed in details
later.

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

N.B. Galactic coordinates are lon=257.1493 lat= +7.9340
and the galactic extinction in R band is about 0.9 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.