GCN Circular 31504
Subject
GRB 220101A: KAO optical-R observation
Date
2022-01-20T14:03:51Z (2 years ago)
From
Ahmed Fouad at NRIAG <ahmed.fouad@nriag.sci.eg>
Ahmed M. Fouad (NRIAG), Ali Takey (NRIAG), Dia Fouda (NRIAG) and
Ola Ali (NRIAG) report:
We observed the optical counterpart of GRB 220101A
(Tohuvavohu et al., GCN 31347; Arimoto et al., GCN 31350)
using 1.88-m telescope at the Kottamia Astronomical Observatory (KAO),
NRIAG, Egypt.
The source was visible at RA: 00:05:24.77, DEC: +31:46:08.7 ,
9.72 arc seconds from the XRT position.
We measured R-Bessel magnitude = 21.5 +/- 0.616
in a combined image of 3x90 seconds images taken at
17:10:00 UT on 3-Jan-2022, 60 hr after the BAT trigger.
Photometry was done based on the brightest 10 stars around the GRB in
a FoV = 8' x 8', selected from the USNO-A1.0 catalog.
The magnitude is not corrected for Galactic extinction
in the direction of the GRB.