TITLE: GCN CIRCULAR NUMBER: 16614 SUBJECT: GRB 140716A: GROND confirmation of the afterglow DATE: 14/07/20 14:54:05 GMT FROM: Sebastian Schmidl at TLS Tautenburg J. Bolmer, F. Knust (both MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We re-observed the field of GRB 140716A (Swift trigger 604792; Cummings et al., GCN 16596) 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 on July 20, 2014, at 09:47 UT, 3.97 days after the GRB trigger. They were performed at an average seeing of 1.8" and at an average airmass of 2.3. Based on a total exposure of 1782 seconds in g'r'i'z', we measure for the optical afterglow candidate reported by Knust et al. (GCN #16601) the following preliminary magnitudes (all AB): g' = 22.9 +/- 0.2 mag, r' = 22.0 +/- 0.1 mag, i' = 21.7 +/- 0.2 mag and z' = 21.2 +/- 0.2 mag. Compared to the first-epoch observations the source has faded in all bands, confirming that this is the optical afterglow of GRB 140716A. Given magnitudes are calibrated against GROND zeropoints and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.13 mag in the direction of the burst (Schlegel et al. 1998).