{
  "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 150120B (D'Elia, et al., GCN 17314) 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 2015/01 21.09 to 2015/01 21.29 UTC (18.73 to\n23.64 hours after the BAT trigger), obtaining a total of 3.91 hours\nexposure in the r, i, and z bands.\n\nFor a source coincident with the GROND optical transient (Wiseman et al.,\nGCN 17336), in comparison with 2MASS, we obtain the following detections\nand upper limit (3-sigma):\n\n  r = 23.4 +/- 0.2\n  i = 22.6 +/- 0.1\n  z > 20.72\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 Astronómico Nacional in San Pedro\nMártir.",
  "createdOn": 1421875475000,
  "version": 2,
  "bibcode": "2015GCN.17343....1B",
  "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>",
  "format": "text/plain",
  "editedOn": 1731009728158,
  "eventId": "GRB 150120B",
  "circularId": 17343,
  "email": "natbutler@asu.edu",
  "subject": "GRB 150120B: RATIR Optical and NIR Observations"
}