{
  "bibcode": "2016GCN.19567....1B",
  "body": "Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William\nH. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier\nProchaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),\nEleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),\nJos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM),\nCarlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),\nJohn Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:\n\nWe observed the field of GRB 160623A (Vianello, et al., GCN 19553) with the\nReionization and Transients Infrared Camera (RATIR; www.ratir.org) on the\n1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on\nSierra San Pedro M��rtir from 2016/06 24.44 to 2016/06 24.47 UTC (29.48 to\n30.31 hours after the BAT trigger), obtaining a total of 0.56 hours\nexposure in the r and i bands and 0.23 hours exposure in the Z, Y, J, and H\nbands.\n\nFor a source on the edge of the Swift-XRT error circle (Mingo, et al., GCN\n19558), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the\nfollowing detections:\n\n  r = 21.12 +/- 0.05\n  i = 19.77 +/- 0.02\n  Z = 18.73 +/- 0.02\n  Y = 18.41 +/- 0.02\n  J = 17.46 +/- 0.01\n  H = 16.93 +/- 0.01\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.  Comparing our images to the finder\nchart reported by Pozanenko, et al. (GCN 19561), we believe this to be the\nsame optical source.  It has apparently faded by about 1 mag in r over the\n~16 hours separating our observations.\n\nThe source is located at RA, Dec = 21:1:11.48, +42:13:14.6 (J2000,\n+/-0.5\").  Further observations are planned.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 19567,
  "createdOn": 1466786920000,
  "email": "natxbutler@gmail.com",
  "subject": "GRB 160623A: RATIR Optical and NIR Observations, Afterglow Confirmation",
  "submitter": "Nat Butler at UC berkeley  <natxbutler@gmail.com>",
  "eventId": "GRB 160623A"
}