GCN Circular 37565
Subject
EP240919a: JinShan optical upper limits
Date
2024-09-20T09:08:37Z (6 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
S.Q. Jiang, J. An, X. Liu, S.Y. Fu, Z.P. Zhu, D. Xu (NAOC), J.Z. Liu (XAO) report on behalf of a large collaboration:
We observed the field of EP240919a detected by EP/WXT (Liang et al., GCN 37561) and likely Fermi/GBM (Liang et al., GCN 37563), using the 100cm-B telescope (100B) of the JinShan project, located at Altay, Xinjiang, China. Observations started at 15:08:25 UT on 2024-09-19, i.e., 14.71 min after the EP/FXT trigger, and a series of frames were obtained in the Sloan r- and i- bands.
No new optical source is detected within the EP/FXT error circle (Liang et al., GCN 37561), down to the following 5-sigma upper limits:
|T_mid(min)|filter|U.L.(AB)|
|47.46 |r| 20.0|
|35.79 |i| 19.5|
calibrated with nearby PanSTARRS stars and not corrected for Galactic extinction.
We acknowledge the excellent support from X. Yao, S.W. Luo, and Z.K. Feng for enabling these observations.