TITLE: GCN CIRCULAR NUMBER: 12169 SUBJECT: GRB110715A: GROND Detection of the Optical/NIR Afterglow DATE: 11/07/18 17:16:47 GMT FROM: Patricia Schady at MPE/Swift A. C. Updike (NASA/GSFC), P. Schady, J. Greiner (both MPE Garching), T. Kruehler (DARK/NBI), D. A. Kann, S. Klose and A. Rossi (all TLS Tautenburg) report on behalf of the GROND team: We observed the field of GRB 110715A (Swift trigger 457330; Sonbas et al., GCN #12158) 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 00:35 UT on 18th July, lasting just under 2hrs and with a midtime ~3dys after the GRB trigger. They were performed at an average seeing of 1.1" and at an average airmass of 1. We found a single point source within the 2.2" Swift-XRT error circle reported by Evans et al. (GCN #12161), consistent with the UVOT position (Kuin et al., GCN #12162). Based on 4136s of total exposures in g'r'i'z' and 4320s in JHK, we estimate preliminary magnitudes (all AB system) of g' = 22.59 +/- 0.09 r' = 21.22 +/- 0.02 i' = 20.53 +/- 0.02 z' = 19.93 +/- 0.02 J = 19.56 +/- 0.24 H = 18.79 +/- 0.17 K = 18.86 +/- 0.31 Given optical and NIR magnitudes are calibrated against GROND zeropoints and 2MASS field stars, respectively, and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E(B-V)=0.60 mag in the direction of the burst (Schlegel et al. 1998).