[vsnet-grb-info 7749] GRB 090429A: GROND upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9303
SUBJECT: GRB 090429A: GROND upper limits 
DATE:    09/04/30 09:16:41 GMT
FROM:    Thomas Kruehler at MPE/MPI  <kruehler at mpe.mpg.de>

F. Olivares, T. Kruehler, J. Greiner (all MPE) report on behalf of the 
GROND team:

We observed the field of GRB 090429A (Swift trigger 350853, Markwardt et 
al.,GCN #9280) simultaneously in g'r'i'z'JHK with GROND mounted at the 2.2m 
ESO/MPI telescope at La Silla Observatory (Chile).

Observations started on 30 Apr. 2009 at 01:05 UT, 20.2 h after the burst, 
and consisted of a set of images with a total integration time of 28 min in 
JHK and 32 min in g'r'i'z'.

In stacked images we do not detect any object inside the enhanced XRT 
errorcircle (Evans et al., GCN #9297) down to the following AB magnitudes:

g' > 23.4
r' > 23.3
i' > 22.6
z' > 22.2
J > 21.8
H > 20.7
K > 20.0

These upper limits have been obtained using 2MASS field stars and the GROND 
zeropoints as reference.