TITLE: GCN CIRCULAR NUMBER: 43916 SUBJECT: GRB 260303A: SVOM/VT optical observations DATE: 26/03/04 01:20:25 GMT FROM: Liping Xin at NAOC, SVOM <xlp@nao.cas.cn> L. P. Xin, Y. N. Ma, H. L. Li, C. Wu, Z. H. Yao, Y. L. Qiu, X. H. Han, J. Wang, Y. Xu, 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/Irfu), Ziqi Wang and Defeng Kong(GXU) report on behalf of the SVOM/VT team. SVOM/VT performed observation with auto slew to the field of GRB 260303A triggered by SVOM/ECLAIRs (sb26030303,Wang et al., GCN 43901). The observation started at 2026-03-03T06:12:27 UTC, i.e. about 9.5 minutes post trigger in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. The optical afterglow reported (Schneider et al., GCN 43902) was clearly detected in both channels. The magnitudes we derived are: mid time (min) | exposure time (s)| band| mag (AB) -------------|-------------------|------ |-------------- 10.4 | 50 | VT_B | 19.29+/-0.05 10.4 | 50 | VT_R | 17.62+/-0.02 47.5 | 50 | VT_B | 20.48+/-0.11 47.5 | 50 | VT_R | 19.51+/-0.07 More detailed analysis is still on going. 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/43916. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...