{
  "bibcode": "2019GCN.26560....1S",
  "body": "R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:\n\nWe observed Swift GRB 191221B (Laha et al., GCN 26534) with the LCO 1-m Sinistro instrument at the Sutherland South African Astronomical Observatory site on December 22, from 00:30 to 01:11 UT (corresponding to 3.5 to 4.2 hours after the GRB trigger time) with the Bessel R and I filters.\n\nWe performed a series of 10x90s exposures in each band. We detect a bright source in the Swift-BAT refined error region (Laha et al., GCN 26536) that is not present in either USNO-B1.0 or 2MASS  surveys with the following  magnitudes:\n\nR = 16.50 +/- 0.01\n\nI = 15.86 +/- 0.01\n\nThis flux measurement is calibrated against several USNO-B1.0 objects near the GRB location and is not corrected for Galactic Extinction.",
  "circularId": 26560,
  "createdOn": 1577038835000,
  "email": "robert.strausbaugh@uvi.edu",
  "subject": "GRB 191221B: LCO Optical Detection",
  "submitter": "Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>",
  "eventId": "GRB 191221B"
}