GCN 42914: EP251130a: JinShan optical observations

L.B. He, J. An, S.Q. Jiang, X. Liu, Z.P. Zhu, D. Xu (NAOC), S.Y. Fu, A.D. Zhu, L. Lei, H.Z. Wu (HUST), J.Z. Liu (XAO) report on behalf of a large collaboration:

We observed the field of EP251130a (Wu et al., GCN 42903) using the 100B telescope of the JinShan project, located at Altay, Xinjiang, China. Obervations started at 2025-11-30 14:13:38 UT, i. e. 3.1 hrs post-burst, and a series of frames in g, r and i bands were obtained.

The previously reported optical counterpart candidate (Dornic et al., GCN 42904) was detected in our stacked i-band frame with a magnitude i = 20.60 +/- 0.18 at a mid-time 4.67 hrs post-burst. The magnitude was callibrated with nearby PanSTARRS1 dr2 catalog and without the Galactic extinction correction.

We acknowledge the excellent support from T.Q. Chen and J.F. Zhang for enabling these observations.