{
  "bibcode": "2018GCN.22564....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 (UVI),\nEleonora Troja (GSFC), 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 180329B (Racusin et al., GCN 22558) 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 2018/03 30.13 to 2018/03 30.18\nUTC (12.92 to 14.22 hours after the BAT trigger), obtaining a total of\n0.96 hours exposure in the r and i bands.\n\nFor a source within the Swift-XRT error circle, in comparison with the\nUSNO-B1 catalog, we obtain the following detections:\n\n r\t= 20.29 +/- 0.09\n i\t= 20.32 +/- 0.10\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nThe source has faded in r at the 4-sigma level when compared to the\nearlier NOT observation of Perley et al. (GCN 22562).\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 22564,
  "createdOn": 1522392082000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 180329B: RATIR Optical Observations",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 180329B"
}