{
  "bibcode": "2019GCN.25971....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 191004A (Barthelmy et al., GCN 25945) with\nthe LCO 1-m Sinistro instrument on September 4, from 20:12 to 20:47 UT\n(corresponding to 1.70 to 2.28 hours from the GRB trigger time)\nwith the Bessel R and I filters.\n\nWe performed a series of 10x180s exposures in each band.  We do not detect a significant source in individual frames, but we do  detect a source in co-added frames that is not present in either USNO-B1.0 or 2MASS surveys and is consistent with the optical afterglow location (Evans et al., GCN 25950) with the following magnitudes:\n\nR = 22.89 +/- 0.10\nI = 21.00 +/- 0.09\n\n\nThis flux is calibrated against several USNO-B1.0 objects near the GRB location but is not corrected for Galactic Extinction.\n\nThese observations were possible thanks to the USVI NASA-EPSCoR\nResearch Infrastructure Development (RID) grant NNX16AL44A.",
  "circularId": 25971,
  "createdOn": 1570464853000,
  "email": "robert.strausbaugh@uvi.edu",
  "subject": "GRB 191004A: Optical Detection with LCO",
  "submitter": "Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>",
  "eventId": "GRB 191004A"
}