M. Nardini, T. Kruehler (both MPE Garching), S. Klose, A. Rossi (both TLS
Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND
We observed the field of GRB 101011A (Swift trigger #436094; Cannizzo et
al. 2010, GCN #11331; Markwardt et al. 2010, GCN #11332) simultaneously in
g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the
2.2 m MPI/ESO telescope on LaSilla. Observations started at 00:10 UT,
October 12, i.e. seven hours after the burst once the field became visible
over La Silla.
In stacked images with a mid-time of 1:06 UT (seeing 2.2 arcsec; mean
airmass 1.8) we do not detect any source at the position of the faint
optical transient seen by UVOT (Holland et al. 2010, GCN #11334) down to
the following limits (3 sigma, AB system):
g' > 24.4,
r' > 23.7,
i' > 22.7,
z' > 22.5,
J > 22.1,
H > 21.5.
These upper limits have been calibrated based on USNO and 2MASS stars.