GCN Circular 12400
A. N. Morgan, C. R. Klein and J. S. Bloom (UC Berkeley) report: We observed the field of GRB 110928A (Hoversten et al., GCN 12394) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2011-Sep-28 02h03m59s UT, ~12.5 min after the Swift trigger. In mosaics (effective exposure time of 678.6 s) taken simultaneously in the J, H, and Ks filters, we do not detect any source within the XRT error circle (Evans et al. GCN 12398). post burst t_mid (hr) exp.(hr) filt U. Limit (3 sig) 0.36 0.19 J > 18.2 0.36 0.19 H > 17.5 0.36 0.19 Ks > 15.9 Deeper NIR observations are underway. All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values.