GRB 200519A: LCO Optical Afterglow Detection

We observed Swift GRB 200519A (Sbarufatti et al., GCN 27756) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory Australia site, on May 9, from 12:39 to 13:02 UT (corresponding to 1.05 to 1.38 hours from the GRB trigger time) with the Bessel R and I filters. We performed a series of 5x120s exposures in R and I. We detect an optical source in stacked images at the UVOT afterglow candidate position position. Using the USNO-B.1 catalog as reference, we calculate the following magnitudes: R = 17.07 +/- 0.02 I = 16.69 +/- 0.02 These magnitudes are not corrected for galactic extinction. R.S. is funded by NSF AST grant #1831682