[vsnet-grb-info 25692] GRB 200522A: LCO Optical Afterglow Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27792
SUBJECT: GRB 200522A: LCO Optical Afterglow Detection
DATE:    20/05/23 18:07:14 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 200522A (Evans et al., GCN 27778) with the LCO 1-m Sinistro instrument at the South African Astronomical Observatory site, on May 23, from 03:20 to 04:20 UT (corresponding to 15.65 to 16.65 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 5x180s exposures in R and I. We detect an optical source in R band, but not I band, in stacked images at the Swift XRT enhanced position (Beardmore et al., GCN 27780).  Using the USNO-B.1 catalog as reference, we calculate the following magnitude and upper limit:

R = 21.49 +/- 0.16

I > 20.39

These magnitudes are not corrected for galactic extinction.

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