TITLE: GCN CIRCULAR NUMBER: 43551 SUBJECT: EP260126a: SVOM/VT optical upperlimit DATE: 26/01/29 07:03:18 GMT FROM: Huali Li at at NAOC, SVOM <lhl@nao.cas.cn> H. L. Li, L. P. Xin, Y. L. Qiu, C. Wu, Y. N. Ma, Z. H. Yao, X. H. Han, Y. Xu, J. Wang, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. R. Xu, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA) report on behalf of the SVOM/VT team. SVOM/VT performed ToO osbervation on EP260126a (Fu et al., GCN 43520). The observation started on 2026-01-26T16:14:40 UT (i.e. 11.837 hour after trigger) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously. No uncatalogued sources are detected in single or stacked images within error box of EP-FXT (Fu et al., GCN 43520). The 3 sigma limit magnitudes are derived as below: Mid time | Band | Exposure Time | 3 sigma limit magnitude 13.907 hour VT_B 29*70 sec >23.4 mag 13.907 hour VT_R 29*70 sec >22.9 mag Our non-detection is consistent with earlier reports from other telescopes (Zhu et al., GCN 43521; Globus et al., GCN 43522; Eyles-Ferris et al., GCN 43523; Eyles-Ferris & Habeeb, GCN 43524; Lee et al., GCN 43525; Taguchi et al., GCN 43541). 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/43551. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...