GCN Circular 37215
Subject
EP240820a: TRT optical upper limit
Date
2024-08-21T08:31:02Z (6 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
J. An, S.Q. Jiang (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), X. Liu, S.Y. Fu, Z.P. Zhu, S.Y. Gao, D. Xu, Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang (NAOC) report on behalf of a large collaboration:
We observed the field of EP240820a (Liang et al., GCN 37214) using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Cerro Tololo Inter-American Observatory, Chile. Observations started at 03:32:49 UTC on 2024-08-21, i.e., 1.11 days after the EP/WXT trigger, and 4 x 240 s frames in R-band were obtained.
No new optical source is detected in the stacked image within the 10-arcsec EP/FXT error circle (Liang et al., GCN 37214), down to a 5-sigma limiting magnitude of R ~ 19.6, calibrated with SkyMapper stars in the field.