GCN Circular 45877

Subject

EP261006a: Xinglong 2.16m/BFOSC optical follow-up observations

Event

EP261006a

Date

2026-10-09T14:54:25Z (a month ago)

Edited On

2026-10-09T19:39:16Z (a month ago)

From

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

Edited By

Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of 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

We performed optical observations of the field of EP261006a (Lao et al., GCN 45826Loading...
 
 ), classified as a possible TDE (Eyles-Ferris et al., GCN 45831Loading...
 
 ; Jiang et al., GCN 45833Loading...
 
 ), in the g, r, and i bands using the 2.16-m telescope located at Xinglong, Hebei, China. In each band, 3 × 300 s exposures were taken, with a median observation time of 2026-10-08T15:35:59, approximately 45.8 hours after the EP-WXT trigger (2026-10-06T17:49:57). We measure preliminary magnitudes of g = 18.49 ± 0.04, r = 19.39 ± 0.15, and i = 19.01 ± 0.08 mag (AB) for the host-subtracted optical counterpart, calibrated against nearby stars from the Pan-STARRS catalog. The stacked g, r, and i images have 5σ limiting magnitudes of ~20.68, 20.41, and 20.10 mag, respectively.
We summarize our observation results as follows:
Obs. No. | Time (UTC) | Exposure Time (s) | Filter | Apparent mag (AB) | Telescope Name 
     1   | 2026-10-08T15:14:46 |  3x300 s |    g   |   18.49 ± 0.04    | 2.16-m telescope  
     2   | 2026-10-08T15:30:51 |  3x300 s |    r   |   19.39 ± 0.15    | 2.16-m telescope   
     3   | 2026-10-08T15:46:46 |  3x300 s |    i   |   19.01 ± 0.08    | 2.16-m telescope