GCN Circular 31321
Subject
GRB 211227A: LCO Optical Observations
Date
2021-12-28T02:51:59Z (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 GRB 211227A (Beardmore, et al., GCN 31316) with the LCO 1-m Sinistro instrument at the Teide, Tenerife site, on December 28, from 00:39 to 01:11 UT (corresponding to 1.12 to 1.48 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 4x240s exposures in R and I bands. We detect no sources within the Swift XRT detection region (Beardmore, et al., GCN 31316) in either band. The following upper limits are calculated using the USNO-B.1 catalog as reference:
R>22.81
I>22.42
We do note the presence of a faint uncatalogued source just outside the XRT region at RA, DEC = (132.1449185, -2.7343489) at the following magnitudes, calculated with respect to the USNO-B.1 catalog:
R=21.79+/-0.20
I=22.13+/-0.24
We recommend continued monitoring of this source to determine if it is fading. These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682