TITLE: GCN CIRCULAR NUMBER: 12349 SUBJECT: GRB 110915A: Deep Near-IR Limits from Magellan DATE: 11/09/16 12:27:01 GMT FROM: Edo Berger at Harvard E. Berger, R. Chornock, J. Strader (Harvard) and L. Spitler (Swinburne) report: "We imaged the field of GRB 110915A (GCN 12335) with the FourStar near-IR imager mounted on the Magellan/Baade 6.5-m telescope starting on 2011 Sep 16.155 UT (14.4 hr after the burst). Observations were obtained in the J and Ks filters in good seeing (0.6"). We do not detect any sources in coincidence with the enhanced XRT position (GCN 12340) to a 3-sigma limit of J>23.5 mag and Ks>23.0 mag (AB). The X-ray flux on the same timescale (extrapolated from the existing XRT light curve) is F_X ~ 4e-12 cgs, indicating an expected near-IR brightness of J~19 mag and K~18.5 mag. If due to extinction, the required ~4.5 mag in J and Ks are suggestive of an unusually large A_V."