{
  "bibcode": "2015GCN.18140....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\n(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico\nRamirez-Ruiz (UCSC), Jos���� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes����s\nGonz����lez (UNAM), Carlos Rom����n-Z��������iga (UNAM), Neil Gehrels (GSFC), and\nHarvey Moseley (GSFC) report:\n\nWe observed the field of GRB 150811A (Evans, et al., GCN 18119) 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 2015/08 13.14 to 2015/08 13.40 UTC (47.37 to\n53.59 hours after the BAT trigger), obtaining a total of 4.93 hours\nexposure in the r, i, and z bands.\n\nWe continue to detect the optical afterglow.  Relative to the flux reported\nin Butler et al. (GCN 18132), the source continues to appear to fade\napproximately as t^(-1).  In comparison with the USNO-B1 and 2MASS\ncatalogs, we obtain the following detections and upper limit (3-sigma):\n\n  r = 22.00 +/- 0.20\n  i = 21.83 +/- 0.20\n  z > 20.40\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nWe thank the staff of the Observatorio Astron����mico Nacional in San Pedro\n M����rtir.",
  "circularId": 18140,
  "createdOn": 1439494104000,
  "email": "natbutler@asu.edu",
  "subject": "GRB 150811A: Continued RATIR Observations",
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>",
  "eventId": "GRB 150811A"
}