GCN Circular 31503
Subject
GRB 211221A: No V & R detection, KAO telescope
Date
2022-01-20T13:50:20Z (3 years ago)
From
Ahmed Fouad at NRIAG <ahmed.fouad@nriag.sci.eg>
Ahmed M. Fouad, Ali Takey & Yosry Azzam at KAO observatory, Egypt report:
The observation of GRB 211221A started on 2021-12-21 from 22:25:01 UT to
23:10:10 UT,
i.e. 1hr_36m_21s to 2hr_21m_30s after the BAT trigger (Evans et al. GCN
Circ. 31273).
No detection of the afterglow in the optical Bessel V & R bands consistent
with the XRT position,
the magnitude limit in the GRB field according to the faintest objects is V
= 22.92 & R = 22.15.
The instrumental magnitudes were computed using aperture photometry in
photutils (python package).