GCN Circular 36710
Subject
EP240618a: TRT optical upper limit
Date
2024-06-20T02:58:48Z (17 days ago)
From
S. Tinyanont at National Astronomical Research Institute of Thailand <samaporn@narit.or.th>
Via
Web form
S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), S.Q. Jiang, J. An, X. Liu, S.Y. Fu, Z.P. Zhu, 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 EP240618a (Sun et al., GCN 36690) using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Sierra Remote Observatory, California, USA. Observations started at 07:37:06.059 UTC on 2024-06-18, i.e., 1.89 hr after the EP trigger, and 15 x 120 s R-band frames were obtained.
No uncatalogued optical transient is detected in the stacked R-band image within the 30-arcsec EP/FXT error circle (Sun et al., GCN 36690), down to a 5-sigma limiting magnitude of R ~ 20.3, calibrated with Pan-STARRS sources in the field. Also there is no apparent brightening for any catalogued source within the EP/FXT error circle.