{
  "body": "Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),\nAlexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM),\nChris Klein (UCB), Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom\n(UCB), Antonino Cucchiara (UCSC), Owen Littlejohns (ASU), Enrico\nRamirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM),\nJesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC),\nand Harvey Moseley (GSFC) report:\n\nWe observed the field of GRB 130518A (Xiong, et al., GCN 14674; Omodei,\net al., GCN 14675) with the Reionization and Transients Infrared Camera\n(RATIR;www.ratir.org) on the 1.5m Harold Johnson Telescope at the\nObservatorio Astronómico Nacional on Sierra San Pedro Mártir from\nfrom 2013/05 19.44 to 2013/05 19.47 UTC (20.54 to 21.49 hours after\nthe GBM trigger), obtaining a total of 0.64 hours exposure in the r'\nand i' bands, 0.27 hours exposure in the Z and Y bands, and 0.15 hours\nexposure in the J, and H bands.\n\nWe detect a new, uncatalogued source at RA,Dec = 355.66781, +47.46493\n(J2000) with an uncertainty of 0.5 arcsec.\nThis position is 5 arcsec from the XRT localization, just outside the\nXRT error circle (Evans, et al., GCN 14678). In comparison with SDSS DR8\nand 2MASS, we obtain the following detections:\n\n     r'    19.38 ± 0.02\n     i'    19.10 ± 0.02\n     Z     18.83 ± 0.04\n     Y     18.65 ± 0.04\n     J     18.28 ± 0.07\n     H     18.47 ± 0.11\n\nThese magnitudes are in the AB system and not corrected for Galactic\nextinction in the direction of the GRB. We have evidence at the 2-3 sigma\nlevel of fading in r' and i' over the duration of our observations.\n\nFurther observations are planned.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir.",
  "version": 2,
  "eventId": "GRB 130518A",
  "createdOn": 1368986348000,
  "submitter": "Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>",
  "circularId": 14679,
  "subject": "GRB 130518A: RATIR Optical and NIR Observations",
  "format": "text/plain",
  "bibcode": "2013GCN.14679....1T",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "email": "eleonora.troja@nasa.gov",
  "editedOn": 1731005861682
}