{
  "bibcode": "2020GCN.27501....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/BAT-GUANO GRB 200405B (DeLaunay et al., GCN 27497) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on April 6, from 08:49 to 09:29 UT (corresponding to 28.9 to 29.6 hours from the GRB trigger time) with the Bessel I and R filters.\n\nWe performed a series of 5x240s exposures in I and R. We do not detect any fading sources in the individual frames (or in stacked images).  We also do not detect any optical counterparts to the 4 potential Swift XRT candidates (Sbarufatti et al., GCN 27500).  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:\n\nR > 21.75\n\nI > 20.86\n\nThese magnitudes are not corrected for galactic extinction.\n\nR.S. is funded by NSF AST grant #1831682",
  "circularId": 27501,
  "createdOn": 1586202086000,
  "email": "robert.strausbaugh@uvi.edu",
  "subject": "GRB 200405B: LCO Optical Upper Limits",
  "submitter": "Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>",
  "eventId": "GRB 200405B"
}