TITLE: GCN CIRCULAR NUMBER: 27858 SUBJECT: GRB 200529A: LCO Optical Afterglow Detection DATE: 20/05/29 13:24:48 GMT FROM: Robert Strausbaugh at U. of the Virgin Islands 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 GRB 200529A (D'Elia et al., GCN 27845) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on May 29, from 10:05 to 10:28 UT (corresponding to 9.15 to 9.53 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 clearly detect an optical source in R band, and force a detection in I band with less than one sigma significance, in stacked images at a location consistent with other optical afterglow detections (Malesani et al., GCN 27846; Zheng et al., GCN 27847). Using the USNO-B.1 catalog as reference, we calculate the following magnitudes: R = 21.76 +/- 0.18 I = 22.82 +/- 1.06 These magnitudes are not corrected for galactic extinction. R.S. is funded by NSF AST grant #1831682