TITLE:   GCN CIRCULAR
NUMBER:  28653
SUBJECT: GRB201015A: Nanshan/NEXT early optical observations
DATE:    20/10/16 14:16:04 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu (NAOC/HUST), X. Liu, S.Y. Fu, D. Xu (NAOC), X. Gao (Urumqi No.1 
Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 201015A (D'Elia et al., GCN 28632) using 
the NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China. 
Observations automatically started at 22:51:31 UT on 2020-10-15, i.e., 
78 s after the BAT trigger. We obtained 3x40s, 4x60s and 12x90s frames 
in the Sloan r-filter until the sky brightens.

The optical afterglow (e.g., Lipunov et al., GCN 28633; Kennea et al., 
GCN 28635; Malesani et al., GCN 28637; Ackley et al., GCN 28639; Hu et 
al., GCN 28645) is clearly detected in our images. The lightcurve rises 
from r = 18.34 +/- 0.08 at T-mid=98 s to the peak of r = 16.97 +/- 0.03 
at T-mid=226 s, and then decays roughly in a powerlaw with the index of 
alpha ~ 1.2. Photometry is calculated with the Pan-STARRS field.