GCN Circular 45205
Subject
EP260723a: SVOM/VT optical observation
Event
Date
2026-07-24T12:08:26Z (2 days ago)
From
Yinuo Ma <mayn@bao.ac.cn>
Via
Web form
Y. N. Ma, L. P. Xin, H. L. Li, Y. L. Qiu, C. Wu, Z. H. Yao, J. R. Xu, X. H. Han, Y. Xu, J. Wang, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, 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 EP260723a detected by EP/WXT (Zhang et al., GCN 45201). SVOM/VT began observing the field at 2026-07-24T05:35:28 UTC, 10.658 hours after the trigger, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.
With X-band data available, the optical counterpart (Eyles-Ferris et al., GCN 45202; He et al., GCN 45203; Basa et al., GCN 45204) was detected in both VT_B and VT_R bands. The AB magnitudes are:
mid time (h) | exposure time (s) | band | mag (AB)
-------------|-------------------|------|---------------
10.98 | 37*50 | VT_B | 22.1+-0.1
10.96 | 29*50 | VT_R | 21.9+-0.2
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.