GCN Circular 19352
T. Schweyer, J. Bolmer, J. Greiner (all MPE Garching), and D. A. Kann (TLS Tautenburg) report on behalf of the GROND team: We observed the field of GRB 160422A (Fermi/GBM trigger 483019143; Yassine et al., GCN #19329) 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 23:02 UT on 22-04-2016, 11.06 hrs after the GRB trigger. They were performed at an average seeing of 2.0" and at an average airmass of 2.2, but also through thick cirrus, which prevented proper measurements in g'r'i'z'. We found a single point source coincident with the 0.45" Swift-UVOT error circle reported by Marshall et al. (GCN #19333). Based on the first 4 min of total exposures in JHK, we estimate preliminary magnitudes (all in AB system) of J = 17.9 +/- 0.3 mag, H = 17.4 +/- 0.3 mag, and K > 17.0 mag. Given magnitudes are calibrated against 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 (Schlafly & Finkbeiner 2011).