GCN Circular 45027
Subject
EP260623a: SVOM/VT optical observations
Event
Date
2026-06-23T12:19:38Z (16 days ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
H. L. Li, L. P. Xin, C. Wu, Y. L. Qiu, J. R. Xu,, Y. N. Ma, Z. H. Yao, 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. T. Palmerio (CEA/Irfu) report on behalf of the SVOM/VT team.
SVOM/VT performed ToO observations to the field of EP260623a triggered by Einstein Probe (Wang et al., GCN 45020). The observation started at 2026-06-10T04:10:37 UTC, about 1.28 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously.
The optical counterpart (Li et al., GCN 45021; Angulo et al., GCN 45024; Brivio et al., GCN 45025; Jiang et al., GCN 45026) with the redshift of z=0.703 (Izzo et al., GCN 45022) was clearly detected by VT in both channels. The following measurements are in the AB magnitude without correction for Galactic extinction:
Mid time | Band | Exposure Time | Brightness
1.283 h VT_B 50 s 17.00 +/- 0.04 mag
1.283 h VT_R 50 s 16.34 +/- 0.04 mag
3.191 h VT_B 50 s 18.59 +/- 0.07 mag
3.191 h VT_R 50 s 17.85 +/- 0.05 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.