TITLE:   GCN CIRCULAR
NUMBER:  32146
SUBJECT: GRB 220527A: AST3-3 Yaoan Optical Observation
DATE:    22/05/28 15:20:11 GMT
FROM:    Tianrui Sun at Purple Mountain Obs,CAS  <trsun@pmo.ac.cn>

Tianrui Sun (Purple Mountain Observatory), Lei Hu, Maokai Hu, Xuefeng Wu, Lei Liu, Kelai Meng, Xiaoyan Li (Nanjing Institute of Astronomical Observation Technology),
Zhengyang Li, Xiangyan Yuan, Lifan Wang (TAMU), Xiaofeng Wang (Tsinghua University), report on behalf the AST3 Team:
    
Following the detection of GRB 220527A detected by AGILE (Ursi et al., GCN 
32129), Fermi (Fermi GBM team, GCN 32130; Bissaldi et al., GCN 32131), CALET (Yamaoka et la., GCN 32139), and AstroSat (Gopalakrishnan et al., 
GCN 32140), we use Antarctic Survey Telescope 3-3 at Yaoan Astronomy Observation (China, Yunnan) to follow up for the afterglow (Sbarufatti et
al., GCN 32135; Tohuvavohu, GCN 32136; Imai et al., GCN 32138; Xu et al.,
GCN 32141; Simon et al. 32143; D'Avanzo et al., 32145).




We observed the target position with 14 x 60s exposure in g-band starting from 27 May 2022, UTC 21:11:36.003, 

about 11.9 hours after the burst.

The magnitude detection at the Swift UVOT position (GCN 32136) on the combined images for the GRB afterglow :
g=19.3 +/- 0.06


We used the PS1 catalogue as the magnitude reference for calibration.