GCN Circular 29520
Subject
GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Assy and Mondy optical observations
Event
Date
2021-02-17T22:55:05Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), V. Kim (FAI, Pulkovo Observatory),
E. Klunko (ISTP), N. Pankov (HSE), M. Krugov (FAI) report on behalf of
GRB IKI FuN:
We continued observation of the ZTF21aagwbjr/AT2021buv transient (Kool
et al., GCN 29405) at the redshift of 0.876 (Xu et al., GCN 29432) which
is an afterglow (Kennea et al., GCN 29413; Teja et al., GCN 29414;
Belkin et al., GCNs 29417, 29438, 29499; Rossi et al., GCN 29433;
Gupta et al., GCN 29490) of GRB 210204A (Fermi GBM team, GCN 29390; Li
et al., GCN 29392; Hurley et al., GCN 29408; Waratkar et al., GCN 29410;
Frederiks et al., GCN 29415). Images in R-filter were obtained at
AZT-33IK telescope of Sayan observatory (Mondy) on Feb.12, 16 and in
r'-filter at AZT-22 telescope of Assy-Turgen observatory on Feb.15, 16.
Preliminary photometry of the optical transient in combined images is
following
Date UT start t-T0 Filter Exp. OT Err. UL(3s) Telescope
(mid, days) (s)
2021-02-12 16:11:09 8.41787 R 20*120 21.66 0.09 22.9 AZT-33IK
2021-02-15 15:40:01 11.40667 r' 70*60 21.86 0.15 23.6 AZT-20
2021-02-16 14:39:53 12.36212 R 31*120 21.8 0.4 21.8 AZT-33IK
2021-02-16 16:57:06 12.44700 r' 32*60 22.18 0.14 23.3 AZT-20
The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1014-0149033 15.43
1014-0149115 17.00
and the same stars from SDSS-DR12
SDSS-DR12
RA DEC g dg r dr
117.03151400 +11.42180300 17.036 0.005 15.624 0.005
117.07973400 +11.41971200 17.909 0.006 17.191 0.006
The updated light curve can be found in
http://grb.rssi.ru/GRB210204A/GRB210204A_lc.png