GCN Circular 46088
Y.Y. Shi(GXU), Z. Kang (CHO), 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), Yifang Liang (PMO), Zhiyong Liu (GZNU) report on behalf of the SVOM/C-GFT team:
We observed the field of GRB 261029A detected by SVOM/ECLAIRs (Goto et al., GCN 46072) with LATIOS on SVOM/C-GFT. Observations started at 2026-10-29T10:14:32 UTC, ~8.79 h after the trigger.
The optical counterpart (O'Neill et al. GCN 46073, He et al. GCN 46078, Wang et al. GCN 46079, De et al. GCN 46080, Cotter et al. GCN 46081, Álvarez et al. GCN46083, Yin et al. GCN 46084) was detected in our images of band g, r and i. The magnitude is:
| [date-obs(mid-time)] | Mid_t-T0(h) | exposure time (s) | band | mag (AB) | mag_err |
|---|---|---|---|---|---|
| 2026-10-29T11:03:05 | 9.60 | 4528s | g | 20.86 | +/- 0.33 |
| 2026-10-29T11:13:55 | 9.78 | 4529s | r | 19.44 | +/- 0.12 |
| 2026-10-29T10:52:16 | 9.42 | 4528s | i | 19.41 | +/- 0.11 |
The photometry was calibrated against Pan-STARRS DR1 catalogue and no correction for Galactic dust extinction was applied.
We thank the observation assistants C.-L. Guo and Y.-H. Hao 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.