GCN Circular 31009
Subject
GRB 211025A: Optical Afterglow Detection
Date
2021-10-26T18:11:21Z (3 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 GRB 211025A (Gropp, et al., GCN 30986) with the LCO 1-m Sinistro instrument at the McDonald Observatory, Texas, USA site, on October 25, from 11:27 to 11:49 UT (corresponding to 6.28 to 6.82 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 4x160s exposures in R and I bands. We detect a source consistent with the Swift UVOT detection coordinates (Oates, et al., GCN 30991) in R-band, but not in I-band. The following magnitudes and upper limits are calculated using the USNO-B.1 catalog as reference:
R=20.51+/-0.27
I>18.04
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682