GCN Circular 44900
Subject
EP260610b: SVOM/VT optical confirmation with blue color
Event
Date
2026-06-11T01:25:37Z (2 days ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
L. P. Xin, H. L. Li, 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 EP260610b triggered by Einstein Probe (Wu et al., GCN 44895). The observation started at 2026-06-10T13:47:19 UTC, 59.5 minutes post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously.
The optical counterpart (Levan et al., GCN 44897) was 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
2.13 h VT_B 91*50 s 22.6 +/- 0.2 mag
2.13 h VT_R 80*50 s 23.0 +/- 0.3 mag
We note the source has a blue color in VT observations.
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.