TITLE: GCN CIRCULAR NUMBER: 40562 SUBJECT: EP250526a: SVOM/VT optical upper limit DATE: 25/05/28 12:59:03 GMT FROM: Liping Xin at NAOC, SVOM <xlp@nao.cas.cn> L. P. Xin, Y. L. Qiu, H. L. Li, C. Wu, Z. H. Yao, Y. N. Ma, X. H. Han, J. Wang, D. Y. Li (NAO, CAS), B.-T. Wang (YNAO, CAS), W. F. Wen (SZTU), J. H. Wu (GZHU), Y. Liu (NAO, CAS) report on behalf of the SVOM and EP mission team SVOM/VT conducted ToO follow-up observations of the EP250526a (Li et al., GCN 40550, Wu et al., GCN 40554). The observation started on 2025-05-27T04:04:19 UT (i.e. 7.66 hour after trigger time) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously.  No uncatalogued source was detected, compared to the Legacy survey, within errorbox of EP-FXT (Li et al., GCN 40550),  down to 3 sigma upper limit of VT_R~23.0 mag (AB) in 16*70 sec stacked images at the mid time of 7.81 hour. The upper limit is consistent with the reports(Lipunov et al., GCN 40551, Angulo et al., GCN 40552). The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/40562. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...