TITLE: GCN CIRCULAR NUMBER: 15381 SUBJECT: GRB 131024B: RATIR Optical and NIR Observations DATE: 13/10/25 15:45:15 GMT FROM: Antonino Cucchiara at UCSC/UCO Lick Antonino Cucchiara (ORAU/GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 131024B (Krimm, et al., GCN 15371) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/10 25.41 to 2013/10 25.52 UTC (12.28 to 14.87 hours after the BAT trigger), obtaining a total of 1.78 hours exposure in the r and i bands and 0.74 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9 and 2MASS, we obtain the following upper limits (3-sigma): r > 23.68 i > 23.35 Z > 22.44 Y > 22.01 J > 21.75 H > 21.49 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.