TITLE:   GCN CIRCULAR
NUMBER:  31774
SUBJECT: GRB 220319A: LCO Optical Upper Limit
DATE:    22/03/20 10:22:27 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 220319A (Page et al., GCN 31769) with the LCO 1-m Sinistro instrument at the Teide Observatory, Tenerife site, on March 19, from 23:48 to March 20, 00:15 UT (corresponding to 5.68 to 6.13 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 3x300s exposures in I and R bands. We do not detect an optical counterpart within the XRT enhanced error region (Goad et al., GCN 31771) in either band, consistent with the non-detection from Mondy (Belkin et. al, GCN 31773). The following upper limits are calculated using the USNO-B.1 catalog as reference:

R>21.44
I>20.47

These magnitudes are not corrected for galactic extinction.

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