TITLE: GCN CIRCULAR NUMBER: 19243 SUBJECT: GRB 160327A: Continued RATIR Optical and NIR Observations DATE: 16/03/28 20:27:50 GMT FROM: V. Zach Golkhou at ASU/RATIR V. Zach Golkhou (ASU), 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 (GSFC/STScI), 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), Harvey Moseley (GSFC), John Capone (UMD), and Vicki Toy (UMD) report: We observed the field of GRB 160327A (Racusin, et al., GCN 19235) 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 2016/03 28.14 to 2016/03 28.39 UTC (17.98 to 24.15 hours after the BAT trigger), obtaining a total of 4.21 hours exposure in the r and i bands and 1.76 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Goad, et al., GCN 19237), in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections: r 23.84 +/- 0.22 i 23.29 +/- 0.14 Z 22.57 +/- 0.20 Y 22.83 +/- 0.35 J 22.43 +/- 0.29 H 21.75 +/- 0.23 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Compared to our previous night of observations (Golkhou et al., GCN 19236), the source flux has decayed substantially in all bands. The source r - i color changes from 2.1 +/- 0.1 to 0.6 +/- 0.3 between our first and the second night observations. The strong color change suggests the possibility of contamination by the GRB host galaxy at late-time. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.