TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4648 SUBJECT: GRB 060203: IR Counterpart DATE: 06/02/04 04:31:02 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom, K. Alatalo (UCB) and C. Blake (Harvard) report: "Starting at 2006-Feb-04 01h41m09 UT we began observing the field of =20 GRB 060203 (GCN 4641) with PAIRITEL. We analyzed the mosaics =20 constructed from the first 918 seconds. Consistent with the XRT =20 position (GCN 4644, 4641) and the suggested OT (GCN 4643, 4645, =20 4646), we find a bright IR counterpart in JHKs with preliminary =20 magnitude: J =3D 17.90 =B1 0.05 H =3D 17.20 =B1 0.06 Ks =3D 16.18 =B1 0.07 Observations continue." This message may be cited.