TITLE: GCN CIRCULAR NUMBER: 43655 SUBJECT: GRB 260208A: SVOM/VT optical observation DATE: 26/02/09 02:31:49 GMT FROM: Yinuo Ma <mayn@bao.ac.cn> Y. N. Ma, L. P. Xin, Y. L. Qiu, C. Wu, H. L. Li, 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. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA) report on behalf of the SVOM/VT team. SVOM/VT performed a Target of Opportunity observation of GRB 260208A detected by Fermi/GBM and Fermi/LAT (Fermi GBM Team, GCN 43635; Sonawane et al., GCN 43642; Longo et al., GCN 43645). SVOM/VT began observing the field at 2026-02-08T13:57:59 UTC, 8.842 hours after the trigger, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. With X-band data available, the optical counterpart (Lipunov et al., GCN 43637; Podesta et al., GCN 43640; Wortley et al., GCN 43641) within Swift/XRT Source 1 errorbox (Dichiara et al., GCN 43652) was clearly detected in both VT_B and VT_R bands. The magnitudes are: mid time (h) | exposure time (s) | band | mag (AB) | mag err -------------|-------------------|------|----------|-------- 10.306 | 23*70 | VT_B | 21.15 | 0.06 10.170 | 19*70 | VT_R | 20.40 | 0.04 Our photometry was not corrected for Galactic extinction. Further SVOM/VT ToO observations are scheduled. 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/43655. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...