{
  "bibcode": "2016GCN.19820....1T",
  "body": "Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),\nAlexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.\nRicher (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC),\nJosh Bloom (UCB), Antonino Cucchiara (GSFC), Owen Littlejohns\n(ASU), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM),\nLeonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-\nZ����iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John\nCapone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:\n\nWe observed the field of GRB 160816A (Mailyan, et al., GCN 19804;\nRacusin, et al., GCN 19802) with the Reionization and Transients\nInfrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson\nTelescope at the Observatorio Astron��mico Nacional on Sierra San\nPedro M��rtir from 2016/08 18.17 to 2016/08 18.47 UTC (1.44 to\n1.72 days after the GBM trigger), obtaining a total of 2.47 hours\nexposure in the r and i bands and 1.03 hours exposure in the Z,\nY, J, and H bands.\n\nFor the source reported in Troja, et al. (GCN 19809), in comparison\nwith the USNO-B1 and 2MASS catalogs, we obtain the following\ndetections and upper limit (3-sigma):\n\n\n    r    22.74 +/- 0.15\n    i    22.40 +/- 0.12\n    Z    22.19 +/- 0.19\n    Y    22.18 +/- 0.25\n    J    > 22.32\n    H    21.20 +/- 0.18\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nThe source intensity decreased significantly between our two epochs,\ncorresponding to fading with power-law index alpha~-1.3 referenced to\nthe burst trigger. This confirms that the candidate reported by\nGuidorzi, et al. (GCN 19808) and Troja et al. (GCN 19809) is the GRB\nafterglow.\n\nDeep imaging of the GRB location reveals additional optical sources\nwithin the XRT localization (Kennea et al., GCN 19806), however none of\nthem have faded.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 19820,
  "createdOn": 1471523704000,
  "email": "eleonora.troja@nasa.gov",
  "subject": "GRB 160816A: RATIR Optical and NIR Afterglow Confirmation",
  "submitter": "Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>",
  "eventId": "GRB 160816A"
}