GCN Circular 45152
Subject
GRB 260619A: SVOM/VT continuous optical observations
Event
Date
2026-07-14T03:36:48Z (a day ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
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) and J. T. Palmerio (CEA/Irfu) report on behalf of the SVOM/VT team.
SVOM/VT performed several ToO observations for GRB 260619A detected by Fermi-LAT (sb26061901, Goto et al., GCN 44985；Dagnoneau et al., GCN 45041). The latest observation started at 2026-07-10T06:53:45 UTC, about 21.196 d 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; Li et al., GCN 45003; He et al., GCN 45008; Malesani et al., GCN 45015) shows significant fading of approximately 1 magnitude in VT_B in the latest observation compared with earlier ones (Li et al., GCN 45003), while remaining stable in VT_R. The following measurements are in the AB magnitude and are not corrected for Galactic extinction:
Mid time | Band | Exposure Time | Brightness
21.24 d VT_B 64*70 s 23.9 +/- 0.3 mag
21.24 d VT_R 63*70 s 22.4 +/- 0.2 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.