GCN Circular 43755
Subject
EP260214b: SVOM/VT optical observation
Event
Date
2026-02-15T16:46:31Z (2 months ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
H. L. Li, Y. N. Ma, L. P. Xin, Y. L. Qiu, C. Wu, Z. H. Yao, X. H. Han, Y. Xu, J. Wang, 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) report on behalf of the SVOM/VT team.
SVOM/VT performed a Target of Opportunity observation of EP260214b detected by Einstein Probe (Yang et al., GCN 43744). The observation started on 2026-02-15T03:52:22 UTC, i.e. 5.81 hours after the trigger, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.
The optical counterpart (He et al., GCN 43745; Watson et al., GCN 43747; Le Floch et al., GCN 43749; Pérez-Fournon et al., GCN 43750; Russeil et al., GCN 43752) were detected in both channels. The measurements in AB magnitude are derived as follows:
Mid time | Band | Exposure Time | 3 sigma limit magnitude
6.93 hours VT_B 80*50 sec 21.29 +/-0.08 mag
6.94 hours VT_R 67*50 sec 20.84 +/- 0.07 mag
The counterpart show no significant variation during our observation from 5.81 hours to 8.08 hours.
Our photometry 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.