GCN Circular 11382
Subject
GRB 101024A: Zadko observatory - Gingin. Optical observations refined analysis
Date
2010-10-26T08:46:02Z (14 years ago)
From
Myrtille LAAS-BOUREZ at U.Western Australia <myrtille.laas@oamp.fr>
GRB 101024A: Zadko observatory - Gingin. Optical observations refined
analysis
-------------------------------------------------------------------------------
M. Laas-Bourez (UWA/ICRAR), A. Klotz (CESR-UPS-CNRS), D. Coward (UWA),
D. Blair (UWA),
M. Boer (OHP-CNRS), P. Thierry (CESR-UPS-CNRS) report:
We analyzed carefully early images of GRB101024A
taken with the Zadko telescope, Gingin, Australia
(see Laas-Bourez et al. 2010 GCNC 11380). Images
are unfiltered. Magnitudes are converted into R
band using the star NOMAD1 0127-0023961 R=13.61
supposing (V-R)=0.6 for the optical counterpart
of the GRB. Magnitudes are not corrected for galactic
dust extinction.
-------------------------------
start end Rmag
(s) (s)
-------------------------------
215 222 16.55 +/-0.15
222 245 16.72 +/-0.15
259 289 16.86 +/-0.12
305 335 17.06 +/-0.12
349 379 17.24 +/-0.12
394 424 17.23 +/-0.12
-------------------------------
Considering a law decay in flux proportional to
t^-alpha, there is a consistent decrease with
alpha ~ 1.1 between 215 and ~ 360 seconds.
After 360 seconds, a plateau seems to be reached
lasting at least 60 seconds.
Compared to the UVOT data taken in the same range
of time (De Pasquale et al. 2010 GCNC 11375) the
optical afterglow is very red, consistent with a
redshift z>2.
This message may be cited.
<http://www.zt.science.uwa.edu.au/>