TITLE: GCN CIRCULAR NUMBER: 17271 SUBJECT: Swift J123205.1-105602: Magellan candidate afterglow DATE: 15/01/03 21:44:34 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona), B. J. Shappee (Carnegie) and E. Berger (Harvard) report: "We observed the location of the short-duration soft burst, Swift J123205.1-105602, detected by Fermi/GBM (Trigger no. 441818617) and Swift/BAT (Cummings; GCN 17267) with the Inamori Magellan Areal Camera and Spectrograph (IMACS) mounted on the Magellan/Baade 6.5-m telescope. We obtained 8x150-sec of r-band observations at a mid-time of 2015 Jan 03.297 UT (1.66 days post-burst) in 0.8" seeing at an airmass of 1.6. Within the XRT position (Cummings et al.; GCN 17268), we detect a faint point-like optical source located at RA(J2000) = 12:32:05.09 Dec(J2000) = -10:56:03.0 with an uncertainty of 1" in each coordinate (registered to 2MASS). We note that this candidate optical afterglow is situated ~3" southeast from the center of a bright catalogued galaxy 2MASX J12320498-1056010, also detected by Swift/UVOT (Cummings et al.; GCN 17268). Further observations are planned to determine the nature of this source."