[vsnet-grb-info 25750] GRB 200524A: Assy continued optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27850
SUBJECT: GRB 200524A: Assy continued optical observations
DATE:    20/05/29 08:45:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI),
M. Krugov (AFIF),  E. Mazaeva  (IKI),  A. Volnova (IKI)  report on
behalf of larger GRB IKI FuN collaboration:

We observed   GRB 200524A (Dirirsa et al., GCN 27797; Pookalil et al., 
GCN 27809; Capalbi  et al., GCN 27811; Gupta et al., GCN 27818) with 
AZT-20 1.5 m telescope  of Assy-Turgen observatory starting on May. 27 
(UT) 17:29:53  in  r'-filter. Optical afterglow discovered by ZTF (Ho et 
al., GCN 27799) and observed by several observations (Kumar et al., GCN 
27800; Rumyantsev et al., GCN 27802; Sanwal et al., GCN 27803; Perley et 
al., GCN 27805; Kumar et al., GCN 27806; de Ugarte Postigo et al., GCN 
27807; Blazek et al., GCN 27810; Ogawa et al., GCN 27813; Izzo, GCN 
27817; Belkin et al., GCN 27820; Kuin et al., GCN 27825).
Preliminary photometry of the afterglow is following

Date       UT start   t-T0      Filter  Exp.    OT    Err.   UL (3sigma)
                        (mid, days)      (s)

2020-05-27 17:29:53   3.55617   r'(AB)  110*60  22.80  0.17  24.4

The photometry is based on the nearby stars of PS1 catalog.