GCN Circular 44639
Subject
EP260514a: TRT optical counterpart candidate
Event
Date
2026-05-16T07:39:15Z (14 days ago)
Edited On
2026-05-17T22:41:06Z (12 days ago)
From
liuxing@nao.cas.cn
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of liuxing@nao.cas.cn
Via
Web form
X. Liu, (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan, K. Noysena, K. Chanchaiworawit (NARIT), S.Q. Jiang, J. An, Z.P. Zhu, L.B. He, D. Xu, Z. Fan, W.X. Li, N.C. Sun (NAOC), S.Y. Fu (HUST) report:
We observed the field of EP260514a dtected by EP/WXT (Cheng et al., GCN 44613; Lipunov et al., GCN 44614; Mohan et al., GCN 44619; Sánchez et al., GCN 44632; Li et al., GCN 44638), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Fresno, California, U.S.A (SRO). Observation started at 2026-05-15 04:25:07 UT, i.e., 0.48 day post-burst, and 6x300 s R-band frames were obtained.
Image subtraction using Legacy-DR10 reveals an uncatalogued optical source within the EP/WXT (Cheng et al., GCN 44613) error circle at coordinates
R.A. (J2000) = 14:17:10.41
Dec. (J2000) = +49:22:30.9
with an uncertainty of ~ 1.5 arcsec. The source had R ~ 21.8 mag with SNR of ~3 at a median time of 11.74 hrs post-trigger, calibrated with Pan-STARRS DR2 converted using Lupton (2005) equations and not corrected for Galactic extinction.
The magnitude is consistent with those reported by SVOM/VT (Li et al., GCN 44638). No NEO would be at the above position at the observational time by checking MPC.
We think the source could be the optical cointerpart of EP260514a.