GCN Circular 46194
Subject
GRB 261108A: SVOM/C-GFT optical upper limit
Event
Date
2026-11-08T15:59:47Z (21 hours ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
S.J. Yin (GXU), Z. Kang (CHO), C. Wu , L.P. Xin (NAOC), Y.X. Guan, Y.Y. Shi(GXU), 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), Y.D. Hu(GXU), Clara Plasse(HKU) report on behalf of the SVOM/C-GFT team:
We observed the field of GRB 261108A detected by SVOM/ ECLAIRs (Xie et al., GCN 46186) with LATIOS on SVOM/C-GFT. Observations started at 2026-11-08T09:20:33.7 UTC, ~ 8.12 hr after the trigger.
We obtained follow-up imaging in g,r and i bands. After preliminary analysis, no credible candidate was detected within the error box provided by SVOM/Eclairs (Xie et al., GCN 46186) in our images. We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction:
g > 19.54 AB (5-sigma, mid-time 8.65 hr after the trigger).
r > 19.53 AB (5-sigma, mid-time 8.84 hr after the trigger).
i > 19.46 AB (5-sigma, mid-time 8.46 hr 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.