GCN Circular 39512
Subject
EP250225a: TRT optical upper limits
Date
2025-02-27T09:15:26Z (10 days ago)
From
Zipei Zhu at NAOC <zpzhu@nao.cas.cn>
Via
Web form
Z.P. Zhu, J. An, X. Liu, S.Q. Jiang, S.Y. Fu (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang, D. Xu (NAOC) report on behalf of a large collaboration:
We observed the field of EP250225a (Jiang et al., GCN 39475) using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Cerro Tololo Inter-American Observatory, Chile. Observations started at 02:45:51 UTC on 2025-02-26, 6 x 300 s and 5 x 300s frames were obtained in Sloan-r and Sloan-z band, respectively.
No new optical source is detected in the stacked images within or beside the ~ 2.8 arc min EP/WXT error circle (Jiang et al., GCN 39475), consistent with the non-detection (Li et al., GCN 39477; Lipunov et al., GCN 39478), down to a 5-sigma limiting magnitude of r ~ 21.8 and z ~ 19.5, calibrated with Pan-STARRS sources in the field and not corrected for Galactic extinction.