TITLE: GCN CIRCULAR NUMBER: 43748 SUBJECT: GRB 260211A: SVOM/VT optical counterpart DATE: 26/02/15 06:50:08 GMT FROM: Huali Li at at NAOC, SVOM <lhl@nao.cas.cn> H. L. Li, Y. N. Ma, C. Wu, Z. H. Yao, Y. L. Qiu, L. P. Xin, 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), R. C. Chen (NJU), A. Li (BNU), W. K. Zheng (UCB) report on behalf of the SVOM/VT team. SVOM/VT performed further ToO observations to GRB260211A detected by SVOM/Eclairs (sb26021102, Gotz et al., GCN 43705) and Fermi GBM (Hamburg et al., GCN 43713). The observation started at 2026-02-14T11:37:39 UTC, i.e., 2.676 days post trigger in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. The source 1 reported in Li et al. (GCN 43720) with coordinations R.A., Dec. (2000)= 86.978758, -0.450528 degrees was fading from 22.5+/-0.3 mag at 2.35 hours to 23.5 +/-0.3 mag at 2.79 days in VT_R channel. The temporal slope is roughly -0.27. Given that the VT source 1 was fading and located within the error box of EP-FXT EPF_J054755.7-002705 (Liang et al., GCN 43721), we propose it is the optical counterpart of the burst. Our photometry was not corrected for Galactic extinction. 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/43748. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...