{
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "format": "text/plain",
  "createdOn": 1366458985000,
  "circularId": 14409,
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),\nWilliam H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB),\nOri Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino\nCucchiara (UCSC), Eleonora Troja (GSFC), 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 130420A (Page, et al., GCN 14406) 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 2013/04 20.41 to 2013/04 20.45 UTC (2.48\nto 3.38 hours after the BAT trigger), obtaining a total of 0.36 hours\nexposure in the r' and i' bands and 0.14 hours exposure in the Z,\nY, J, and H bands.\n\nFor a source within the Swift-XRT error circle, in comparison with SDSS DR8\nand 2MASS, we find:\n\nr'\t19.81 +/- 0.02\ni'\t19.41 +/- 0.02\nZ\t19.37 +/- 0.06\nY\t18.99 +/- 0.07\nJ\t19.16 +/- 0.07\nH\t18.87 +/- 0.11\n\nThese magnitudes are in the AB system and not corrected for Galactic\nextinction in the direction of the GRB.  Uncertainties are 1-sigma.\n\nComparison to the earlier photometry of Morgan et al. (GCN 14408) shows that this source has faded by about 2.5 magnitudes in J and H.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro \nMártir.\n-- \nDr. Alan M. Watson\nInstituto de Astronomía\nUniversidad Nacional Autónoma de México",
  "eventId": "GRB 130420A",
  "bibcode": "2013GCN.14409....1W",
  "subject": "GRB 130420A: RATIR Optical and NIR Observations",
  "editedOn": 1731005622952,
  "email": "alan@astro.unam.mx",
  "version": 2
}