GCN Circular 45372
Subject
EP260812a: SVOM/C-GFT optical upper limit
Event
Date
2026-08-13T06:50:14Z (2 days ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
S.J. Yin (GXU), Z. Kang (CHO), Y.X. Guan (GXU), C. Wu (NAOC), L.P. Xin, X.H. Han, P.P. Zhang, X.M. Lu (NAOC), Z.W. Li, Y. Lv (CHO), R.S. Zhang, Y.J. Xiao, Y.L. Qiu, J. Wang, J.S. Deng, L. Huang, J.Y. Wei (NAOC) report on behalf of the SVOM/C-GFT team:
We observed the field of EP260812a detected by EP-WXT (Liu et al., GCN 45362) with LATIOS on SVOM/C-GFT. Observations started at 2026-08-12T11:28:12 UTC, ~ 7.2 minutes after the trigger.
We obtained r-band follow-up imaging（Poor weather interrupted the observations, affecting image quality）. After preliminary analysis，no credible candidate was detected within the error box provided by EP-WXT (Liu et al., GCN 45362) in our images. We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction:
r > 18.3 AB (3-sigma, mid-time 27.5 min after the trigger).
We thank the observation assistants B.-W. Li and H.-X. Xue at Jilin observatory for their excellent support.
The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcmin x 21 arcmin FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching.