{
  "bibcode": "2013GCN.15223....1B",
  "createdOn": 1379047310000,
  "circularId": 15223,
  "eventId": "GRB 130907A",
  "format": "text/plain",
  "version": 2,
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>",
  "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>",
  "subject": "GRB 130907A: Continued RATIR Optical and NIR Observations",
  "email": "natbutler@asu.edu",
  "editedOn": 1731009137807,
  "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 130907A (Page et al., GCN 15183) 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 2013/09 13.13 to 2013/09 13.16 UTC (125.49 to\n126.24 hours after the BAT trigger), obtaining a total of 0.36 hours\nexposure in the r and i bands and 0.15 hours exposure in the Z, Y, J, and H\nbands.\n\nFor the source reported in Lee et al. (GCN 15192), in comparison with SDSS\nDR9 and 2MASS, we obtain the following upper limits (3-sigma) in the AB\nmagnitude system (not corrected for Galactic extinction in the direction of\nthe GRB) :\n\n  r     > 22.68\n  i     > 22.62\n  Z     > 21.30\n  Y     > 20.70\n  J     > 20.42\n  H     > 19.69\n\nWe conclude from our most constraining limit (i-band), that the source has\nfaded by at least 0.9 mags since our observation 2 nights ago (Butler et\nal., GCN 15209).  These magnitudes are now significantly fainter than the\nDR9 catalog magnitudes of SDSS galaxy mentioned by Lee et al.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir."
}