{
  "bibcode": "2017GCN.22057....1W",
  "body": "Alan M. Watson (UNAM), Eleonora Troja (GSFC), Nat Butler (ASU),\nAlexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer\n(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),\nAntonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz\n(UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Harvey\nMoseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki\nToy (UMD) report:\n\nWe observed the field of GRB 171027A (D'Avanzo et al., GCN Circ. 22053)\nwith the Reionization and Transients Infrared Camera (RATIR;\nwww.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio\nAstron��mico Nacional on Sierra San Pedro M��rtir from 2017/10 27.35 to\n2017/10 27.37 UTC (0.04 to 0.51 hours after the BAT trigger), obtaining\na total of 0.36 hours exposure in the r and i bands and 0.15 hours\nexposure in the Z, Y, J, and H bands.\n\nFor a source within the Swift-XRT error circle, in comparison with the\nUSNO-B1 and 2MASS catalogs, we obtain the following detections and upper\nlimits (3-sigma):\n\n  r\t> 23.17\n  i\t> 23.12\n  Z\t> 20.66\n  Y\t> 21.09\n  J\t= 20.95 +/- 0.26\n  H\t= 19.12 +/- 0.06\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB. The source position is at RA,\nDec (J2000) = 04:06:45.77 -02:37:18.9 (+/- 0.5 arcsec). We currently\nhave no evidence for fading.\n\nThe very red colors suggest that this might be at high redshift or\ndusty.\n\nFurther observations are planned.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 22057,
  "createdOn": 1509103205000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 171027A: RATIR Detection of a NIR Afterglow Candidate",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 171027A"
}