TITLE: GCN CIRCULAR NUMBER: 14047 SUBJECT: GRB 121209A: PAIRITEL NIR Observations DATE: 12/12/10 03:07:55 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan (UC Berkeley) reports: We observed the field of GRB 121209A (Maselli et al., GCN 14045) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2012-Dec-10 01h16m41s UT, ~3.2 hours after the Swift trigger. In mosaics (effective exposure time of 1940 s) taken simultaneously in the J, H, and Ks filters, we do not detect any source within the XRT error circle. post burst t_mid (hr) exp.(hr) filt U. Limit (3 sig) 3.68 0.54 J > 18.1 3.68 0.54 H > 17.2 3.68 0.54 Ks > 16.2 All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values.