{
  "bibcode": "2020GCN.26957....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 (UVI), Eleonora\nTroja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes��s\nGonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Harvey Moseley (GSFC), John\nCapone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:\n\nWe observed the field of GRB 200131A (Sbarufatti et al., GCN 26953) with\nthe Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on\nthe 1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional\non Sierra San Pedro M��rtir from 2020/02 1.10 to 2020/02 1.14 UTC (3.79 to\n4.61 hours after the BAT trigger), obtaining a total of 0.64 hours exposure\nin the r and i bands.\n\nThe optical transient (see, also, Lipunov et al., GCN  26954) is\nwell-detected.  We find:\n\n  r = 19.97 +/- 0.04\n  i = 19.75 +/- 0.02\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 26957,
  "createdOn": 1580531172000,
  "email": "natxbutler@gmail.com",
  "subject": "GRB 200131A: RATIR Optical Observations",
  "submitter": "Nat Butler at UC berkeley  <natxbutler@gmail.com>",
  "eventId": "GRB 200131A"
}