TITLE:   GCN CIRCULAR
NUMBER:  10956
SUBJECT: GRB 100713A: GROND upper limits
DATE:    10/07/14 10:11:51 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

M. Nardini, T. Kruehler, and J. Greiner  (all MPE Garching) report on behalf
of the GROND team:
  
We observed the field of GRB 100713A (INTEGRAL trigger 6041; Mereghetti et
al., GCN #10951) 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 at La Silla
Observatory (Chile).
  
Observations started at 23:46 UT on 2010 July 13th, 9.3 h after the GRB
trigger. They were performed at an average seeing of 2.6" and at an
average airmass of 2.5. With a total integration time of 13.2 min (12 min 
for the IR), we do not detect any source within the Swift-XRT error circle 
reported by D'Elia et al. (GCN #10952) down to

g' > 23.8,
r' > 22.9,
i' > 22.0,
z' > 21.5,
J  > 18.8,
H  > 17.4 and
K  > 16.8

The given limits are derived based on calibrating the images against USNO
B1 catalogue and 2MASS field stars and are not corrected for the Galactic
foreground extinction corresponding to a reddening of E_(B-V)= 0.056 in  
the direction of the burst (Schlegel et al. 1998). 

We  confirm the presence of a faint source close to the border of the XRT
error circle at the coordinates reported by D'Avanzo et al. (GCN 10954).