GCN Circular 3507
D. Kaplan (MIT), P. Garnavich (Notre Dame), J. Rosenberg (CfA) and K.Z. Stanek (CfA, Ohio State) The field of GRB 050525a (Band et al. GCN 3466) was imaged with the PANIC infrared camera on the Baade telescope of the Magellan Observatory on May 26 and 27 (UT) and we detect the afterglow (Rykoff et al. GCN 3465;3468) in the Ks-band on both nights. Using the 2MASS calibrated stars in the field we find the afterglow on May 26.278 (UT) to have Ks=19.2+/-0.1. We also have properly calibrated the FLWO observation obtained on May 25 (Rosenberg & Garnavich GCN 3471) and combined all three nights of data. We find that the afterglow light curve in the K-band is well represented by a power-law decay with a slope of -1.6 and Ks=18.75 one day after the burst. This message may be cited.