TITLE: GCN CIRCULAR NUMBER: 19131 SUBJECT: GRB 160303A: RATIR Optical and NIR Afterglow Detection DATE: 16/03/03 13:07:10 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 160303A (Beardmore, et al., GCN 19126) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2016/03 3.46 to 2016/03 3.52 UTC (1.8 minutes to 1.50 hours after the BAT trigger), obtaining a total of 1.02 hours exposure in the r and i bands and 0.44 hours exposure in the Z, Y, J, and H bands. We detect an uncatalogued source within the Swift-XRT error circle, in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections and upper limits (3-sigma): r = 22.95 +/- 0.31 i = 22.65 +/- 0.23 Z > 21.98 Y = 21.83 +/- 0.36 J > 21.30 H > 21.01 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The source is located at RA, Dec = 11:14:48.12, +22:44:32.6 (J2000, +/-0.5"). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.