[vsnet-grb-info 25751] GRB 200524A: SAO RAS optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27851
SUBJECT: GRB 200524A: SAO RAS optical observations
DATE:    20/05/29 09:29:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

S. Belkin (IKI), A. Moskvitin (SAO RAS), A. Pozanenko (IKI), 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 
Zeiss-1.0 m telescope  of SAO RAS observatory  in  Rc-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 is following

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

2020-05-27 21:48:28   3.71143   Rc      2400   22.54  0.20  23.6
2020-05-28 22:17:40   4.73171   Rc      2400   n/d    n/d   22.6

The photometry is based on the nearby stars of SDSS DR12 catalog and 
Lupton' transformation gri -> R.