{
  "bibcode": "2016GCN.19663....1W",
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),\nWilliam H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.\nXavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara\n(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico\nRamirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM),\nJes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC),\nHarvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and\nVicki Toy (UMD) report:\n\nWe observed the field of GRB 160705B (Cannizzo et al., GCN 19657) with\nthe Reionization and Transients Infrared Camera (RATIR; www.ratir.org)\non the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico\nNacional on Sierra San Pedro M��rtir from 2016/07 6.17 to 2016/07 6.21\nUTC (7.04 to 8.05 hours after the BAT trigger), obtaining a total of\n0.66 hours exposure in the r and i bands and 0.30 hours exposure in the\nZ, Y, J, and H bands.\n\nWe detect two sources within the enhanced Swift-XRT error circle\n(Osborne et al., GCN 19659). The brighter source is an uncataloged source\nat 11:12:26.20 +46:42:01.2 (J2000, +/- 0.5 arcsec) with the following\ndetections and 3-sigma upper limit:\n\nr = 22.89 +/- 0.15\ni = 22.12 +/- 0.09\nZ = 22.34 +/- 0.33\nY = 21.73 +/- 0.32\nJ > 21.54\nH = 20.98 +/- 0.34\n\nThe fainter source is a cataloged SDSS source at 11:12:26.42 +46:41:59.6\n(J2000, +/- 0.5 arcsec) with the following detections and 3-sigma upper\nlimits:\n\nr = 23.39 +/- 0.24\ni = 22.61 +/- 0.14\nZ = 22.10 +/- 0.26\nY > 21.87\nJ > 21.54\nH > 21.04\n\nThese magnitudes are in the AB system, are in comparison with the SDSS\nDR9 and 2MASS catalogs, and are not corrected for Galactic extinction in\nthe direction of the GRB.\n\nWe note that Guidorzi et al. (GCN 19658) report an uncataloged source\nwith r of about 21 at 36 minutes after the burst trigger. Their source\nis only 0.7 arcsec from our brighter uncataloged source and so we\npostulate that these correspond to the afterglow of the GRB. The\nafterglow has faded by about 2 magnitudes between their observations at\n36 minutes and ours at 7.54 hours, which corresponds to a temporal index\nof about -0.6.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 19663,
  "createdOn": 1467813049000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 160705B: RATIR Optical and NIR Observations and Confirmation of the Fading Afterglow",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 160705B"
}