{
  "bibcode": "2015GCN.17595....1B",
  "format": "text/plain",
  "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 150317A: RATIR Optical Afterglow Detection",
  "version": 2,
  "email": "natbutler@asu.edu",
  "createdOn": 1426603310000,
  "editedOn": 1731008523100,
  "circularId": 17595,
  "eventId": "GRB 150317A",
  "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), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús\nGonzález (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and\nHarvey Moseley (GSFC) report:\n\nWe observed the field of GRB 150317A (Siegel, et al., GCN 17592) 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 2015/03 17.18 to 2015/03 17.43 UTC (3 minutes\nto 5.9 hours after the BAT trigger), obtaining a total of 3 hours exposure\nin the r, i, and z bands.\n\nWe find an uncatalogued source within the Swift-XRT error circle (Evans et\nal., GCN 17594).  In comparison with the SDSS DR9 and 2MASS, we obtain the\nfollowing detections and upper limit (3-sigma):\n\n  r     20.5 +/- 0.1\n  i     21.7 +/- 0.1\n  z     > 20.8\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.  This photometry is preliminary and\ncan be expected to improve with a more detailed analysis due to the\nproximity of a bright star (e.g., Xu, et al., GCN 17593).\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir.",
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>"
}