GCN Circular 35935
Subject
X-ray transient EP240315a: Nanshan/HMT optical upper limit
Date
2024-03-17T06:52:41Z (a month ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
S.Q. Jiang, Z.P. Zhu, X. Liu, J. An, S.Y. Fu, T.H. Lu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report on behalf of a large collaboration:
We observed the field of EP240315a detected by Einstein Probe (EP, Zhang et al., GCN 35931) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. We obtained 30 x 90 s frames without any filter.
No uncatalogued optical transient is detected within or near the EP/WXT error circle, down to a limiting magnitude of r ~ 20.9 at a median time of 20.44 hr post-trigger, calibrated with the nearby PanSTAR field.
The previously reported ATLAS optical counterpart candidate, AT2024eju, (Srivastav et al., GCN 35932) is not present in the HMT co-added image, indicating that it has decayed significantly. Our non-detection is consistent with that from LT (Srivastav et al., GCN 35933).