TITLE: GCN CIRCULAR NUMBER: 16534 SUBJECT: GRB140706A: GROND detection of the Optical/NIR afterglow DATE: 14/07/07 10:05:11 GMT FROM: Patricia Schady at MPE/Swift P. Schady (MPE Garching), S. Klose (TLS Tautenburg) and J.Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 140706A (Swift-603587; Marshall et al., GCN #16531) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 09:01UT on 7th-July, 13.5 hours after the GRB trigger, and are continuing. They were performed at an average seeing of 1.3” and at an average airmass of 1.5. We found a single point source within the 2.2" Swift-XRT enhanced error circle reported by Beardmore et al. (GCN #16532) consistent with the UVOT position (Marshall et al., GCN #16531). Based on the first 8 min exposure, we estimate preliminary magnitudes (all in AB system) of g' = 22.4 +/- 0.1 mag, r' = 22.1 +/- 0.1 mag, i' = 21.9 +/- 0.1 mag, z' = 21.5 +/- 0.1 mag, J > 20.9 mag, H > 20.3 mag, and K > 18.8 mag. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlegel et al. 1998).