TITLE: GCN CIRCULAR NUMBER: 19233 SUBJECT: GRB 160325A: GROND Upper Limits DATE: 16/03/26 01:22:14 GMT FROM: Corentin Delvaux at MPE C. Delvaux (MPE Garching), D. A. Kann (TLS Tautenburg), F. Knust, and J. Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 160325A (Swift trigger 680436; Sonbas et al., GCN #19222, Fermi GBM detection, Roberts, GCN #19924, Fermi LAT detection, Axelsson et al., GCN #19227) 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 23:29 UT on 25/03/2016, 16.5 hrs after the GRB trigger. They were performed at an average seeing of 1.7" and at an average airmass of 2.3. We do not detect the source reported by Fugazza et Melandri (GCN #19223) down to the following magnitudes (in AB system): g > 22.4 mag, r > 22.5 mag, i > 22.3 mag, z > 22.4 mag, J > 20.3 mag, H > 19.8 mag, and K > 18.5 mag. Given upper limits 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)=0.1 mag in the direction of the burst (Schlafly & Finkbeiner 2011).