TITLE:   GCN CIRCULAR
NUMBER:  37940
SUBJECT: GRB 241029A: Xinglong-2.16m optical afterglow confirmation
DATE:    24/10/29 14:45:50 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

S.Q. Jiang, Z.P. Zhu, S.Y. Fu, J. An, X. Liu, L.P. Xin, X.H. Han, J. Wang, D. Xu, C. Wu, J.Y. Wei (NAOC) report:

We observed the field of GRB 241029A detected by Fermi/GBM (Fermi GBM team, GCN 37932), SVOM/ECLAIRs & SVOM/GRM  (Schanne et al., GCN 37934; Wang et al., GCN 37935) using the 2.16m telescope located at Xinglong, Hebei, China, equipped with the BFOSC camera. Observations started at 13:17:07 UT on 2024-10-29, i.e., 10.95 hr after the SVOM/ECLAIRs trigger, and a series of 360 s frames were obtained in R-band.

The previously reproted optical source (Jiang et al., GCN 37937; Lin et al., GCN 37939) is clearly detected in the stacked image, and it has decayed to R = 20.52 +/- 0.04 at 11.21 hr after the SVOM/ECLAIRs trigger, calibrated with nearby PanSTARRS stars and not corrected for Galactic extinction. We thus think the source is the optical afterglow of the burst.  

We thank the great support of the Xinglong-2.16m staff, in particular Yinan Zhu and Jie Zheng.