GCN Circular 33187
Subject
GRB 230116D: SAO RAS redshift
Date
2023-01-17T15:29:14Z (a year ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Moskvitin (SAO RAS), A. Pozanenko (IKI), A. Moiseev (SAO RAS), D.
Oparin (SAO RAS), S. Belkin (IKI, HSE) report on behalf of larger
collaboration:
We observed the optical afterglow (Zhu et al., GCN 33177; Nazarov et
al., GCN 33178; Moskvitin et al., GCN 33179; Swain et al., GCN 33182) of
GRB 230116D (Sonbas et al., GCN 33176) with BTA SAO RAS telescope
equipped with SCORPIO-2. Observation started on 2023-01-16 (UT)
23:31:38. Spectroscopic observations consists of 10x600 s exposures with
940@600 grizm.
We detect a sharp break at 5850 AA and afterglow continuum up to 7200
AA. We interpret the sharp break due to H I. Over the continuum we
identified multiple absorption features, which we interpret as due to S
II, Si II, O I, C II, Si IV at a common redshift of z = 3.81.