GCN Circular 44896
Subject
EP260610a: SVOM/VT optical upper limits
Event
Date
2026-06-10T14:40:01Z (2 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 a ToO observation of the field of EP260610a triggered by Einstein Probe (Wu et al., GCN 44889). The observation started at 2026-06-10T05:47:51 UTC, i.e., about 1.18 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously.
No uncatalogued optical source was detected at the FXT source position (Wu et al., GCN 44889) in our stacked images, compared to the Legacy Survey. The 3-sigma upper limits are:
Mid_time Band Exposure Time Magnitude (AB)
2.27 h VT_B 83*50 s > 23.8 mag
2.27 h VT_R 84*50 s > 23.4 mag
The magnitudes are in the AB system and are not corrected for Galactic extinction.
Our non-detection is consistent with the observation from COLIBRÍ (Postigo et al., GCN 44890).
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.