TITLE: GCN CIRCULAR NUMBER: 40709 SUBJECT: EP 250612a: AST3-3 Yaoan Optical Observation DATE: 25/06/12 16:49:28 GMT FROM: ylhua@pmo.ac.cn Yan-Long Hua, Tian-Rui Sun, Lei Hu, Jin-Jun Geng, Xue-Feng Wu (PMO, CAS), report on behalf the AST3 Team: Following the detection of EP 250612a detected by Einstein Probe (Hua et al., GCN 40700), and its potential gamma-ray counterpart by Fermi (Fermi GBM team, GCN 40702), we use Antarctic Survey Telescope 3-3 at Yaoan Astronomy Observation (China, Yunnan) to follow up for the afterglow. We observed the target position with 30 x 180s exposure in g-band starting from 2025-06-12T13:12:59.95 about 0.75 hours after the burst. No new optical source was detected within the error box (Hua et al., GCN 40700) down to 20.27 mag in the coadd image (total 30x180s, g-band). View this GCN Circular online at https://gcn.nasa.gov/circulars/40709. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...