TITLE:   GCN CIRCULAR
NUMBER:  27733
SUBJECT: GRB 200512A: LCO Optical Upper Limits
DATE:    20/05/13 20:46:43 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 200512A (Simpson et al., GCN 27726) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on May 13, from 19:03 to 19:25 UT (corresponding to 23.50 to 23.87 hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 5x120s exposures in R and I. We do not detect any fading sources in the individual frames (or in stacked images).  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:

R > 20.90

I > 20.29

These magnitudes are not corrected for galactic extinction.

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