[vsnet-grb-info 28123] GRB 210610B: optical photometry of afterglow at INASAN/Simeiz

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30226
SUBJECT: GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
DATE:    21/06/12 19:16:14 GMT
FROM:    Mansur Ibrahimov at INASAN  <mansur at inasan.ru>

M. Ibrahimov, M. Nalivkin, I. Nikolenko (all from INASAN, 
Moscow, Russia) and O. Pons (IGA, Havana, Cuba) report on 
behalf of a larger team:



Using Zeiss 1m telescope and 4K FLI PL16803 CCD of Simeiz 
Obserbatory (Collective Using Center of INASAN), we 
observed the field of GRB 210610B (Page et al., GCN 
30170). 15x120sec images were acquired through Bessel R 
filter on 2021-06-11/00:03:07 UT (midpoint time, 4.18 
hours after the trigger) with a total exposure time of 
1800 sec.



Optical afterglow (for a list of the most full references 
see e.g. Hosokawa et al., GCN 30220 and Anandagoda et al., 
GCN 30221) was clearly seen in all 15 individual R images.



Photometry of the optical afterglow using stacked R-image 
calibrated against USNO-B1 R1-mag of 2 nearby stars, 
resulted in: R = 17.61 +/- 0.02 mag.



Research was supported by Project No. RFMEFI61319X0093 
(Russian Ministry of Science and High Education, Agreement 
No. 075-15-2019-1716 by 2019 Nov 20) and Project No. 
19-29-11013 (Russian Foundation of Fundamental 
Investigation, Agreement No. 19-29-11013\20 by 2021 Jan 
21).