TITLE: GCN CIRCULAR NUMBER: 9283 SUBJECT: GRB 090429B: GROND Observations DATE: 09/04/29 07:58:36 GMT FROM: Aybuke Kupcu Yoldas at ESO F. Olivares (MPE Garching), A. Kupcu Yoldas (ESO), J. Greiner, T. Kruehler, A. Yoldas (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 090429B (Swift trigger 350854; Ukwatta et al., GCN #9281) 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 05:43 UT, ~13 minutes after the GRB trigger and continued until the source reached the 20 deg horizon limit. They are performed at an average seeing of 1.2 and at an average airmass of 2.5. We do not detect any source within the Swift-XRT error circle reported by Ukwatta et al. (GCN #9281) down to the following limits (based on 4 minutes of exposure time, all in AB system): g' > 23.4 mag r' > 23.3 mag i' > 22.4 mag z' > 21.8 mag J > 21.5 mag H > 20.2 mag K > 19.6 mag Quoted upper limits have been derived using USNO and 2MASS field stars as reference.