[vsnet-grb-info 25336] GRB 200324A: LCO Optical Upper Limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27436
SUBJECT: GRB 200324A: LCO Optical Upper Limit
DATE:    20/03/25 07:21:16 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh at 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 200324A (Dichiara et al., GCN 27428) with the LCO 1-m Sinistro instrument at the McDonald Observatory, USA site, on March 25, from 6:06 to 6:46 UT (corresponding to 13.28 to 13.95 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 do not detect any sources in the individual frames (nor in stacked images) in the Swift enhanced error region (Beardmore et al., GCN 27430), consistent with other optical non-detections.  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:

R > 24.21

I > 22.56

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