TITLE: GCN CIRCULAR NUMBER: 43923 SUBJECT: GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate DATE: 26/03/05 15:06:48 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) report on behalf of the SVOM/VT team. SVOM/VT performed further ToO observations of GRB 260211A detected by SVOM/Eclairs and SVOM/GRM (sb26021102, Gotz et al., GCN 43705). Also there was a sub-threshold detection by Fermi GBM (Hamburg et al., GCN 43713). The observations were performed on 2026-03-03 and 2026-03-05 in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously. The optical counterpart (Li et al., GCN 43720, GCN 43748) was measured to have a brightness of VT_R=22.91+/-0.25 mag at 19.36 days post trigger and VT_R=22.85+/-0.25 mag at 21.31 days respectively. These measurements show that the counterpart is rebrightening, relative to the reported brightness (Li et al. GCN 43748). We suggest that it is likely the supernova associated with the burst. Further follow-up observations are encouraged. Our photometry was in AB magnitude and 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/43923. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...