TITLE:   GCN CIRCULAR
NUMBER:  27321
SUBJECT: GRB 200306A: Potential LCO Optical Afterglow Detection
DATE:    20/03/06 06:15:31 GMT
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 GRB 200306A (Simpson et al., GCN 27320) with the LCO 1-m Sinistro instrument at the Cerro Tololo Interamerican Observatory, Chile site, on March 6, from 1:06 to 1:46 UT (corresponding to 0.78 to 1.45 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 detect a faint source in stacked R band images within the XRT error region that is not present in USNO or 2MASS catalogs.  We do not detect a source in stacked I band images.  Using the USNO-B.1 catalog as reference, we obtain the following magnitude detection in R at RA,DEC=101.1054814,-62.0049360 and the following 3-sigma upper limit in I:

R = 21.75

I > 21.52

R.S. is funded by NSF AST grant #1831682