GCN Circular 31503
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).