TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4045 SUBJECT: GRB 050820A: NIR photometry at the TNG DATE: 05/09/28 17:08:00 GMT FROM: Stefano Covino at Brera Astronomical Observatory F. Mannucci, S. Covino, D. Malesani, on behalf of the CIBO collaboration report: We observed the field of GRB 050820A (Page et al., GCN 3830) in the NIR at the TNG equipped with NICS on the 21st of August at 05:00 UT, about 22.4 hours after the high-energy event. The OT identified by Fox et al. (GCN 3829) is clearly visible with J magnitude: J = 18.48 +/- 0.08 Calibration has been derived by comparison with a suitable number of 2MASS stars in the field. This message can be cited.