TITLE: GCN CIRCULAR NUMBER: 17613 SUBJECT: GRB 150323A: RATIR Optical Afterglow Observations DATE: 15/03/23 04:09:49 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), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), 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 150323A (Amaral-Rogers, et al., GCN 17611) 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 2015/03 23.12 to 2015/03 23.16 UTC (9.6 to 58.8 minutes after the BAT trigger), obtaining a total of 42.6 minutes exposure in the r, i, and z bands. For the source on the edge of the Swift-XRT error circle (Cenko et al., GCN 17612), in comparison with the SDSS DR9, we obtain the following measurements and upper-limit (3-sigma): r = 21.16 +/- 0.11 i = 20.39 +/- 0.05 z > 19.30 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We note that this source appears to be fading during our observation. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.