{
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>",
  "circularId": 14496,
  "version": 2,
  "bibcode": "2013GCN.14496....1B",
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "body": "Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William\nH. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB)\nJ. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),\nEleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),\nJosé A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM),\nCarlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)\nreport:\n\nWe observed the field of GRB 130427B (Maselli, et al., GCN 14460) with the\nReionization and Transients Infrared Camera (RATIR; www.ratir.org) on the\n1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on\nSierra San Pedro Mártir from 2013/04 28.44 to 2013/04 28.48 UTC (21.26 to\n22.19 hours after the BAT trigger), obtaining a total of 0.71 hours\nexposure in the r' and i' bands and 0.29 hours exposure in the Z, Y, J, and\nH bands.\n\nFor a source within the Swift-XRT error circle (Osborne, et al., GCN\n14467), in comparison with USNO-B1 and 2MASS, we obtain the following upper\nlimits (3-sigma):\n\n  r' > 22.08\n  i' > 22.06\n  Z  > 21.28\n  Y  > 20.77\n  J  > 20.57\n  H  > 19.84\n\nThese limits,  in the AB system and not corrected for Galactic extinction\nin the direction of the GRB, were derived from PSF-fitting photometry,\nbecause of the presence of a 16.5 magnitude star only 5 arcseconds to the\nsouth of the SWIFT-XRT source position.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir.",
  "subject": "GRB 130427B: RATIR Optical and NIR Observations",
  "createdOn": 1367199593000,
  "email": "natbutler@asu.edu",
  "editedOn": 1731009052715,
  "format": "text/plain",
  "eventId": "GRB 130427B"
}