TITLE:   GCN CIRCULAR
NUMBER:  13697
SUBJECT: GRB 120821A: GROND upper limits
DATE:    12/08/22 09:47:54 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

P. Schady (MPE Garching), S. Klose (TLS Tautenburg) and J. Greiner (MPE
Garching) report on behalf of the GROND team:

We observed the field of GRB 120821A (INTEGRAL trigger #6266; Mereghetti
et al., GCN #13696) 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 23:47 UT, 10.4 hours after the GRB trigger. They
were performed at an average seeing of 1.1" and at an average airmass of
1.0.

The GROND JHK observations fully covered the INTEGRAL error circle,
whereas the g'r'i'z observations covered ~60% of the error circle. We do
not detect any obvious new source brighter than the detection limits of
DSS2 and 2MASS within the area covered by the 2arcmin INTEGRAL error
circle.