{
  "subject": "GRB 130420A: Continued RATIR Optical and NIR Observations",
  "email": "alan@astro.unam.mx",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "editedOn": 1731009314001,
  "createdOn": 1366665763000,
  "bibcode": "2013GCN.14439....1W",
  "eventId": "GRB 130420A",
  "circularId": 14439,
  "version": 2,
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),\nWilliam H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori\nFox (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 again observed the field of GRB 130420A (Page et al., GCN Circular\n14406) with the Reionization and Transients Infrared Camera (RATIR;\nwww.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio\nAstronómico Nacional on Sierra San Pedro Mártir from 2013/04 22.35 to\n2013/04 22.47 UTC (48.84 to 51.69 hours after the BAT trigger),\nobtaining a total of 0.71 hours exposure in the r' and i' bands and 0.29\nhours exposure in the Z, Y, J, and H bands.\n\nThe afterglow is again detected in several bands.  In comparison with\nSDSS DR8 and 2MASS, we obtain:\n\nr' 22.63 +/- 0.17\ni' 22.46 +/- 0.17\nZ  21.62 +/- 0.25\nY > 21.32\nJ > 21.39\nH > 20.91\n\nThese magnitudes are in the AB system, quoted with 1-sigma uncertainty,\nand not corrected for Galactic extinction in the direction of the GRB. \nThe upper limits are at the 3-sigma level.\n\nIn comparison with our earlier observations (Watson et al., GCN Circular\n14409; Butler et al., GCN Circular 14431), we see that the afterglow\nfaded by about 2 magnitudes from about 3 to about 25 hours after the\nSwift trigger, but then by only about another 0.5 magnitudes from about\n25 to about 50 hours after the Swift trigger.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir.",
  "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>"
}