TITLE: GCN CIRCULAR NUMBER: 14352 SUBJECT: GRB 130327A: RATIR Optical/NIR afterglow confirmation DATE: 13/03/29 00:21:46 GMT FROM: Antonino Cucchiara at UCSC/UCO Lick Antonino Cucchiara (UCSC), 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), 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 reobserved the field of GRB 130327A (Ukwatta et al., GCN 14331, and Osborne et al., GCN 14335) 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 2013/03 28.13 to 2013/03 28.14 UTC (25.24 to 25.64 hours after the BAT trigger), obtaining a total of 0.33 hours exposure in the r' and i' bands and 0.14 hours of exposure in the Z, Y, J, and H bands. The source identified in our previous RATIR observations within the refined XRT error circle (Butler et al. GCN 14334), and detected by Gemini (source #2 in GCN 14342) has faded below our detection limit. We report the following 3-sigma limits in the AB magnitude system: r' > 22.67 i' > 22.46 Z > 20.83 Y > 20.47 J > 20.07 H > 19.99 This fading is consistent with the fading reported by Cucchiara et al. (GCN 14342). Based on these observations we confirm that this was the optical/NIR afterglow of GRB 130327A. The second source identified outside the refined XRT error circle in the first RATIR observation and detected also by Gemini (as source #1 in GCN 14342) has not faded. Therefore it is unrelated to GRB 130327A. These magnitudes 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. [GCN OPS NOTE(29mar13): Per author's request, the name in the Subject-line was changed from "130727A" to "130327A".]