TITLE:   GCN CIRCULAR
NUMBER:  28769
SUBJECT: GRB 201020B: follow-up observations at Konkoly
DATE:    20/10/24 11:11:02 GMT
FROM:    Jozsef Vinko at Konkoly Observatory  <vinko@konkoly.hu>

J. Vinko (Konkoly/ELTE/U Szeged), A. Pal, L. Kriskovics, R. Szakats, A. Ordasi and K. Vida (Konkoly) 
report on behalf of the "Transient Astrophysical Objects" project:

Follow-up observations of the optical afterglow of GRB 201020B 
(Fermi team, GCN 28702; Lipunov et al. GCN 28704; 
Malacaria and Meegan, GCN 28710; Ursi et al. 28714; Arimoto et al., GCN 28716; 
Lipunov et al., GCN 28718; Xu et al., GCN 28719; Ridnaia et al., GCN 28723;  
Belkin et al., GCN 28725; Sbarufatti et al., GCN 28740; Breeveld et al., GCN 28743;
Vinko et al. GCN 28750; Kumar et al. GCN 28753; Kann et al. GCN 28765; Belkin et al.
GCN 28768) with the 0.8m RC80 telescope at Konkoly Observatory yielded the following magnitudes
for the transient: 

Date         UT-mid    t-T0(hr)   Exp(s)   Filter   AB mag     Err
2020-10-22   19:31:01  49.94      6 x 300  SDSS-r   20.592  0.172
2020-10-22   19:36:07  50.04      6 x 300  SDSS-i   20.566  0.264

tied to local PS1 stars. 

Our data are consistent with the magnitudes reported by Belkin et al. (GCN 28768).
At the redshift of z=0.8 (Kann et al. GCN 28765) these correspond to
M ~ -22.9 absolute mag.