TITLE: GCN CIRCULAR NUMBER: 43720 SUBJECT: GRB 260211A: SVOM/VT optical observation DATE: 26/02/13 09:02:26 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 ToO observation to GRB260211A detected by SVOM/Eclairs (sb26021102, Gotz et al., GCN 43705) and Fermi GBM (Hamburg et al., GCN 43713). The observation started at 2026-02-11T20:48:38 UTC, i.e., 1.41 hours post trigger in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. SVOM/VT performed ToO observation to GRB260211A detected by SVOM/Eclairs (sb26021102, Gotz et al., GCN 43705) and Fermi GBM (Hamburg et al., GCN 43713). The observation started at 2026-02-11T20:48:38 UTC, i.e., 1.41 hours post trigger in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. Following EP-FXT's detections, two optical candidates were detected only in VT_R images compared to the PanSTARRS catalogue: Source1 : R.A., Dec. (2000)= 86.978758, -0.450528 4.7 arcsecs from the center of FXT src-1 Source2 : R.A., Dec. (2000)= 86.977490, -0.453334 17.9 arcsecs from the center of FXT src-1 The positions are given with an uncertainty of 0.5 arcsec. The measurements in AB magnitudes are given below: ID. Mid time. Band Exposure Time Magnitude (AB) Source1. 2.35 hour VT_R 16*70 sec 22.5+/-0.3 mag 5.63 hour VT_R 12*70 sec >22.6 mag 1.52 hour VT_B 16*70 sec >23.0 mag 5.95 hour VT_B 6*70 sec >22.5 mag Source2. 2.35 hour VT_R 16*70 sec 21.9+/-0.2 mag 5.63 hour VT_R 12*70 sec 21.9+/-0.2 mag 1.52 hour VT_B 16*70 sec >23.0 mag 5.95 hour. VT_B 6*70 sec >22.5 mag Our photometry was not corrected for Galactic extinction. For source2, we notice that there is a faint source in the PanSTARRS image. More followup observation is encouraged to confirm the nature of the sources. 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/43720. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...