GCN Circular 31995
Subject
GRB 220427A: LCO Optical Observations
Date
2022-05-03T18:41:20Z (2 years ago)
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 GRB220427A (D'Ai et al. GCN 31960) with the LCO 1-m Sinistro instrument at the South African Astronomical Observatory site, on April 27, from 22:57 to 23:24 UT (corresponding to 1.95 to 2.40 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 detect an optical counterpart at the location of the Swift optical counterpart that is consistent with other optical detections (Ugarte Postigo, et al., GCN 31967; Klotz, et al., GCN 31991). The following magnitudes are calculated using the USNO-B.1 catalog as reference:
R=20.35+/-0.12
I=20.15+/-0.30
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682