TITLE: GCN CIRCULAR NUMBER: 45003 SUBJECT: GRB 260619A: SVOM/VT optical counterpart confirmation DATE: 26/06/19 14:30:00 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, J. R. Xu, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA/Irfu), Kuan Liu (GXU), Zhiyong Liu (GZNU) report on behalf of the SVOM/VT team. SVOM/VT performed ToO observations of GRB260619A triggered by SVOM/ECLAIRs (sb26061901, Goto et al., GCN 44985). The observation started at 2026-06-19T05:54:32 UTC, approximately 3.71 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously. The optical candidate (Ducoin et al., GCN 44999) was detected in both channels. The following measurements are in the AB magnitude and are not corrected for Galactic extinction: Mid time | Band | Exposure Time | Brightness 6.13 h VT_B 14*70 s 22.56 +/- 0.15 mag 6.14 h VT_R 13*70 s 22.63 +/- 0.18 mag 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/45003. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...