TITLE:   GCN CIRCULAR
NUMBER:  28003
SUBJECT: GRB 200613A: Continued CrAO optical observations
DATE:    20/06/21 10:36:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI),�� V. Rumyantsev (CrAO),�� A. Volnova 
(IKI), E. Mazaeva (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the�� GRB 200613A (Fermi GBM team, GCN 27926; Bissaldi et 
al., GCN 27930; Ohno et al., GCN 27931; Yamaoka Ohno et al., GCN 27964)�� 
with ZTSH 2.6m telescope of CrAO observatory starting on 2020-06-20 (UT) 
19:19:12.�� The optical afterglow (e.g., Kann et al., GCN 27935; 
Pozanenko et al., GCN 27937; Izzo et al., GCN 27939; Zhu et al., GCN 
27943; Marshall, GCN 27944; Liu et al., GCN 27949; Belkin et al., GCN 
27958) is detected in a stacked image. Preliminary photometry of the 
afterglow is following

Date������������ UT start�� t-T0������ Filter Exp.���� OT������ Err. UL
 �������������������������������������� (mid, days)�������� (s)
2020-06-20 19:19:12�� 6.58142 R���������� 6*120 21.13 0.10 22.7

The photometry is based on nearby SDSS star
SDSS-DR12_id���������� R(Lupton)
J101207.75+454443.4 17.877

A light curve of the afterglow of�� GRB 200613A can be found in 
http://grb.rssi.ru/GRB200613A/GRB200613A_lc_v2.png