TITLE: GCN CIRCULAR NUMBER: 36868 SUBJECT: JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star DATE: 24/07/15 08:41:14 GMT FROM: Dong Xu at NAOC/CAS <dxu@nao.cas.cn> S.Q. Jiang, S.Y. Fu, Z.P. Zhu, X. Liu, J. An, L.B. He, D. Xu (NAOC), J.Z. Liu (XAO) report on behalf of a large collaboration: We observed the filed of the X-ray transient (RA=336.513, DEC=-15.302) triggered by the Wide-field X-ray Telescope (WXT) on board Einstein Probe (EP) at 17:12:56 UT on 2024-07-14 (Zhang et al., GCN 36867). Observation started at 17:56:29 UT on 2024-07-14, i.e., 43.6 mins after the EP-WXT trigger and ended at 18:55:24 UT on 2024-07-14, and a series of short exposures were obtained in the Sloan r-band at the 50D telescope of the JinShan project, located at Altay, Xinjiang, China. The high proper motion star, LP 820-19, within the Follow-up X-ray Telescope (FXT) 10 arcsec error circle and considered likely the optical counterpart of this EP trigger (Zhang et al., GCN 36867), is clearly detected in our first 3 s exposure. It has r = 12.00 +/- 0.01 mag, much brighter than its archival magnitude of r = 16.24 +/- 0.01 mag in PanSTARRS, confirming it is in the flaring status. The star has r ~ 13.0 mag in our last exposure, still much brighter than its PanSTARRS magnitude. In addition, we didn't find any new optical transient in our stacked image within the FXT error circle, down to the limiting magnitude of r ~ 20.1 mag. Hence we confirm that this EP trigger is due to the flaring star LP 820-19. We acknowledge the excellent support from S.W Luo, M.M. Yang, Z. K. Feng, Q. C. Zhao and L.F. Huo for enabling these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/36868. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...