GCN Circular 27501
Subject
GRB 200405B: LCO Optical Upper Limits
Date
2020-04-06T19:41:26Z (5 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We 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.
We 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:
R > 21.75
I > 20.86
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682