GCN Circular 15547
S. Schmidl, S. Klose, A. Nicuesa Guelbenzu (TLS Tautenburg), and J. Greiner (MPE Garching) report: We observed the field of GRB 131128A (Swift trigger 579683; Sonbas et al., GCN 15533) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 00:27 UT on November 29, about 9.5 hrs after the GRB trigger and were performed under moderate seeing conditions (1.6") and moderate airmass (2.3). For the optical afterglow discovered by Xu et al. (GCN 15535, 15537) we measure RA, DEC (J2000) = 23:41:13.795, +31:18:22.32 (+/- 0.2"), and r'(AB) = 22.6 +/- 0.1, calibrated against SDSS field stars (mean time 01:12 UT). Photometry in the other GROND bands is affected by a bright star very close to the afterglow. It might be improved once second-epoch data are obtained.