TITLE: GCN CIRCULAR NUMBER: 14077 SUBJECT: GRB 121211A: RATIR Optical and NIR Observations DATE: 12/12/13 04:12:26 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), Chris Klein (UCB), Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Eleonora Troja (GSFC), Enrico Ramirez‐Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 121211A (Mangano, et al., GCN 14057) 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 2012 Dec 12.48 to 2012 Dec 12.58 UTC (21.8 to 24.1 hours after the BAT trigger), obtaining a total of 1.8 hours exposures in the r' and i' bands and 0.67 hours of exposure in the Z, Y, J, and H bands. In comparison with SDSS DR8 and 2MASS, we derive the following detections and upper limits (3-sigma) in the AB magnitude system: r' 22.9 +/- 0.2 i' 23.2 +/- 0.2 Z 22.1 +/- 0.4 Y >21.3 J >21.9 H >21.1 These magnitudes are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.