GCN Circular 35396
Subject
GRB 231216A: Nanshan/HMT optical upper limit
Date
2023-12-18T14:59:03Z (5 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
email
J. An, S.Y. Fu, S.Q. Jiang, X. Liu, Z.P. Zhu, T.H. Lu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 231216A detected by Swift (Sbarrato et al., GCN 35378) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 18:42:32 UT on 2023-12-16, i.e., 6.83 mins after the Swift/BAT trigger, and a series of 20, 40, 60, 90, 120, 200 s frames were obtained without any filter.
No optical source is detected in our stacked image at the XRT position (Sbarrato et al., GCN 35378), down to the 3-sigma limiting magnitude of m(r) > 20.2 mag (AB) @ 26.03 mins post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter. The magnitude is not corrected for Galactic extinction.