GCN Circular 43734
Subject
EP260213a: SVOM/VT optical upper limit
Event
Date
2026-02-14T11:22:32Z (a month 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 EP260213a detected by Einstein Probe (Yang et al., GCN 43729; Li et al, GCN 43730). The observation started on 2026-02-13T21:19:03 UTC, 1.346 hours after the trigger, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.
No uncatalogued sources were detected in stacked images within the error box of EP-FXT (Yang et al., GCN 43729; Li et al., GCN 43730). The 3 sigma limit magnitudes are derived as follows:
Mid time | Band | Exposure Time | 3 sigma limit magnitude
2.38 hour VT_B 72*50 sec > 23.7 mag
2.39 hour VT_R 67*50 sec > 23.5 mag
Our photometry was in AB magnitude and was not corrected for Galactic extinction.
The nondetection is consistent with the results published previously (Cotter et al., GCN 43728; Wu et al., GCN 43731; Maksut et al., GCN 43732; Pankov et al., GCN 43733).
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.