TITLE:   GCN CIRCULAR
NUMBER:  8492
SUBJECT: GRB 081105: GROND Upper Limits
DATE:    08/11/07 07:53:48 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, R. Filgas, J. Greiner, T. Kruehler, A. Yoldas (all MPE Garching), 
A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on 
behalf of the GROND team:

We observed the field of GRB 081105 (Swift trigger #333811; Cummings et al., 
GCN #8484) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).

Observations started at 02:01 UT on November 6th, 2008, 12.6 hr after the GRB 
trigger with 23.0 min of total exposures in g'r'i'z' and 24.0 min in JHK. 
They were performed at an average seeing of 1.4" and at an average airmass of 
1.2.

As Ugarte Postigo et al. (GCN #8489), we do not detect any object within the 
4.8'' Swift-XRT error circle reported by Beardmore et al. (GCN #8487) down to 
the following upper limits (all in AB system) of:

g' > 23.3 mag,
r' > 23.2 mag,
i' > 22.5 mag,
z' > 22.3 mag,
J > 21.6 mag,
H > 21.0 mag and
K > 20.0 mag.

These upper limits are derived based on calibrating the images against the 
GROND zeropoints as well as 2MASS field stars.