TITLE:   GCN CIRCULAR
NUMBER:  31504
SUBJECT: GRB 220101A: KAO optical-R observation
DATE:    22/01/20 14:03:51 GMT
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.