GCN Circular 46023
Subject
EP261023a: J band upper limit by SYSU 80cm infrared telescope
Event
Date
2026-10-25T09:05:37Z (2 days ago)
From
zhanghr33@mail2.sysu.edu.cn
Via
Web form
Hao-Ran Zhang, Shu-Quan Bai, Zhong-Nan Dong, Rui-Chen Gao, Si-Rui Huang, Jin-Ji Li, Jia-Qi Lin, Pu Lin, Yun Shi, Jing-Kai Sun, Zhi-Xiang Tan, Lu-Yao Wen, Hao-Nan Yang, P. H. Thomas Tam, Rong-Feng Shen, and Bin Ma (Sun Yat-sen University) report on behalf of the SYSU 80cm infrared telescope team:
We observed the field of EP261023a detected by the Einstein Probe (Yang et al., GCN 46014), with the Sun Yat-sen University 80cm infrared telescope in the J band. The observations were carried out on 2026-10-24 from 11:55:12 to 12:58:45 UT, beginning 31.87 hr after the EP-WXT trigger. A total of 157 frames of 20s each were stacked, giving 3140s on source.
We do not detect any new source within the optical afterglow localization (RA, Dec = 3.984, +51.5986 deg, J2000; 0.4 arcsec uncertainty; reported by NOT, Lei et al., GCN 46015) in our stacked image, and obtain a 5-sigma upper limit of J = 19.1 mag (Vega). Observation by Mondy started on ~9.8 hr after the trigger also yield a 3-sigma upper limit of R = 22.2 mag (Pankov et al., GCN46018).
The SYSU 80cm infrared telescope is operated and managed by the Department of Astronomy, Sun Yat-sen University.