{
  "bibcode": "2013GCN.15209....1B",
  "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),\nJos� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes�s Gonz�lez (UNAM),\nCarlos Rom�n-Z��iga (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 Astron�mico Nacional on\nSierra San Pedro M�rtir from 2013/09 11.12 to 2013/09 11.16 UTC (77.18 to\n78.08 hours after the BAT trigger), obtaining a total of 0.71 hours\nexposure in the r and i bands and 0.30 hours exposure in the Z and Y.\n\nFor the source reported in Lee et al. (GCN 15192), in comparison with SDSS\nDR9 and 2MASS, we obtain the following detections and upper limits\n(3-sigma):\n\n  r     22.40 +/- 0.14\n  i     21.73 +/- 0.10\n  Z     > 21.80\n  Y     > 21.05\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.  The source has faded by about 0.4\nmags in the r and i bands relative to our observations last night (Butler\net al., GCN 15208).\n\nWe thank the staff of the Observatorio Astron�mico Nacional in San Pedro\nM�rtir.",
  "circularId": 15209,
  "createdOn": 1378876463000,
  "email": "natbutler@asu.edu",
  "subject": "GRB 130907A: Continued RATIR Optical and NIR Observations",
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>",
  "eventId": "GRB 130907A"
}