TITLE: GCN CIRCULAR NUMBER: 21472 SUBJECT: GRB 170813A: RATIR Optical and NIR Observations DATE: 17/08/13 20:13:16 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 170813A (Page, et al., GCN 21468) 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 2017/08 13.15 to 2017/08 13.18 UTC (2.48 to 3.06 hours after the BAT trigger), obtaining a total of 0.36 hours exposure in the r and i bands and 0.15 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Osborne, et al., GCN 21469), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 22.46 i > 22.08 Z > 20.23 Y > 19.82 J > 19.38 H > 19.13 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.