GCN Circular 45856

Subject

EP261007a/GRB 261007A：Xinglong optical observation

Event

Date

2026-10-08T11:02:58Z (8 hours ago)

From

Xinglong Observatory at National Astronomical Observatories (NAOC), Chinese Academy of Sciences (CAS) <xinglong@nao.cas.cn>

Via

Web form

Junbo-Zhang (NAOC), Junjie-Jin (NAOC), Rui-Zhu (NAOC), Haiyang-Mu (NAOC), Feng-Xiao (NAOC), Yuguang-Sun (NAOC), Jie-Zheng (NAOC), Dong-Xu (NAOC), Zhou-Fan (NAOC), Hong-Wu (NAOC) report on behalf of a large collaboration

Following the detection of GRB 261007A by SVOM (Goto et al., GCN 45824

) and EP261007a by EP-WXT (Wen et al., GCN ), we observed the field of EP261007a/GRB 261007A using the 2.16-m telescope at Xinglong Observatory, NAOC. We obtained 6x300s clear-band frames with a median time of 2026-10-07 15:09:20 (UT) (8.37 h after the EP trigger and 9.45 h after the SVOM trigger).

The stacked clear-band image using the 2.16-m telescope has a 5-sigma limiting magnitude of ~21.33 mag, calibrated with the Pan-STARRS field. And the optical afterglow was detected in our stacked frame with a magnitude of 20.044 +- 0.071 mag.