TITLE: GCN CIRCULAR NUMBER: 13143 SUBJECT: GRB 120326A: PAIRITEL NIR Observations DATE: 12/03/27 18:22:24 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan (UC Berkeley) reports: We observed the field of GRB 120326A (Siegel et al., GCN 13105) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2012-03-27 09:25:19 UT, ~32.1 hours after the Swift Trigger. In mosaics (effective exposure time of 1.31 hours) taken simultaneously in the J, H, and Ks filters, we detect a source at the optical afterglow location (Klotz et al., GCN 13107; LaCluyze et al., GCN 13109; Guidorzi et al., GCN 13111; Walker et al., GCN 13112; Kuin et al., GCN 13114; Im et al., GCN 13117; Hentunen et al., GCN 13119; Urata et al., GCN 13121; Zhao et al., GCN 13122; Soulier, GCN 13126; Jang et al., GCN 13139; Quadri et al., GCN 13142). The preliminary photometry yields: post burst t_mid (hr) exp.(hr) filt mag m_err 33.58 1.31 J 17.5 0.1 33.58 1.31 H 16.7 0.1 33.58 1.31 Ks 16.0 0.2 All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values. Further observations are ongoing.