TITLE: GCN CIRCULAR NUMBER: 19088 SUBJECT: GRB 160225A: RATIR Optical and NIR Observations DATE: 16/02/26 07:25:27 GMT FROM: Nat Butler at Az State U 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 160225A (Siegel, et al., GCN 19075) 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 2016/02 26.13 to 2016/02 26.28 UTC (12.72 to 16.34 hours after the BAT trigger), obtaining a total of 2.47 hours exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H bands. We detect the WHT afterglow candidate (Wiersema, et al., GCN 19082), and find it to have faded. In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections and upper limits (3-sigma): r > 24.09 i = 23.03 +/- 0.16 Z = 22.17 +/- 0.19 Y > 22.35 J = 22.06 +/- 0.33 H > 21.74 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The r-band faintness suggests that this may be a moderate to high-z source. Fitting Milky Way, LMC, and SMC Exctinction Laws in Addition to the IGM (see, Littlejohns, et al. 2014), we find a photo-z of 5.54 (+0.35,-5.11; 90% conf.). Hence, a high-z solution is preferred, but a low-z origin is not ruled out. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.