GCN Circular 15091
Subject
GRB 130812A: GROND upper limits
Event
Date
2013-08-13T13:19:03Z (13 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
K. Varela (MPE Garching), D.A. Kann (TLS Tautenburg), J. Greiner
(MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 130812A (Swift trigger 566228;
D'Elia et al. 2013, GCN #15088) simultaneously in g'r'i'z'JHK with
GROND (Greiner et al. 2008, PASP 120, 405) mounted at the
2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
Observations started at 10:13 UT on 13 Aug. 2013, 11.8 hrs after the
GRB trigger. They were performed at an average seeing of 2.5" and at
an average airmass of 1.4.
In 212 sec exposure in g'r'i'z' and 360 sec exposure in JHK
we do not detect a source within the 1.8 arcsec Swift-XRT error
circle reported by Evans et al. (2013; GCN #15089) down to
(all in the AB system)
g' > 22.4,
r' > 22.6,
i' > 21.9,
z' > 21.7,
J > 20.3,
H > 19.4 and
K > 18.8
The given limits are derived based on calibrating the images against
GROND zeropoints and 2MASS field stars and are not corrected for the
Galactic foreground extinction corresponding to a reddening of
E_(B-V)= 0.23 in the direction of the burst (Schlegel et al. 1998).