TITLE: GCN CIRCULAR NUMBER: 40719 SUBJECT: GRB 250610B: J band upper limit by SYSU 80cm infrared telescope DATE: 25/06/13 13:43:34 GMT FROM: zengxt27@mail2.sysu.edu.cn Xiang-Tao Zeng, Duo-Le Cao, Chun Chen, Zhong-Nan Dong, Jia-Qi Lin, Wei-Sen Huang, Jin-Ji Li, Xia Li, Pu Lin, Hao-Nan Yang, Yan Yu, Hao-Ran Zhang, P H Thomas Tam, Rong-Feng Shen, Bin Ma (Sun Yat-sen University) report on behalf of the SYSU 80cm infrared telescope team: We observed the field of GRB 250610B (Saccardi et. al., GCN 40671; Evans et. al., GCN 40679; Liang et. al., GCN 40681) using the Sun Yat-sen University 80cm infrared telescope with 51 x 20 s exposures in J band. The calculated position is RA. = 200.1744 deg, DEC = 31.1751 deg J2000, from SVOM observation. Our observations began at 2025-6-10 16:55:00 UTC, 22 minutes after the SVOM trigger. We do not detect any counterpart at the position of the optical afterglow (Wang et al., GCN 40672, Gompertz et al., GCN 40674, Schneider et al., GCN 40676, Gompertz et al., GCN 40677, Li et al., GCN 40678, Brivio, et al., GCN 40687, Schneider, et al., GCN 40689, Adami, et al., GCN 40698), down to a 5-sigma depth of J~ 17 Vega magnitudes. The SYSU 80cm infrared telescope is operated and managed by the Department of Astronomy, Sun Yat-sen University. View this GCN Circular online at https://gcn.nasa.gov/circulars/40719. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...