[vsnet-grb-info 3742] GRB 060919: TAROT optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5576
SUBJECT: GRB 060919: TAROT optical observations
DATE:    06/09/19 09:49:17 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 imaged the field of GRB 060919 detected by SWIFT
(trigger 230115) with the new TAROT robotic telescope (D=25cm)
located at the La Silla observatory, Chile.

First image was acquired 28.3s after the GRB trigger
(5.2s after the notice). The field elevation decreased
from only 2 degrees above horizon and weather conditions
were good. Images were taken during the prompt emission.

Date of trigger : t0 = 2006-09-19T07:48:38.880

First image is 60.0s exposure trailed. No OT is visible:
t0+28.3s to t0+88.3s : R > 15.4

Second image is 30.0s exposure. No OT is visible:
t0+94.2s to t0+124.2s : R > 15.8

We co-added a series of the 3
firsts not trailed exposures. No OT is visible:
t0+94.2s to t0+196.4s : R > 15.9

Fourth non trailed image is a 90.0s exposure
and covers the second gamma peak described by
Guidorzi et al. GCNC 5575. No OT is visible:
t0+292.3s to t0+382.3s : R > 15.8

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

N.B. Galactic coordinates are lon=343.8526 lat=-17.2471
and the galactic extinction in R band is 0.5 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.