GCN Circular 46143
Subject
EP261103a: NOT optical counterpart candidate
Event
Date
2026-11-04T05:13:44Z (a day ago)
From
sqjiang at NAOC <sqjiang@bao.ac.cn>
Via
Web form
S.Q. Jiang, D. Xu, J. An, L.B. He, X. Liu, Z.P. Zhu (NAOC), S.Y. Fu, L. Lei, A.D. Zhu (HUST), J.P.U. Fynbo (DAWN/NBI), A. Caballero Almagro, F. Mustafaj (NOT) report:
We observed the field of EP261103a detected by EP/WXT (Ren et al., GCN 46142) using the the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 9 x 120 s Sloan r-filter images.
An uncatalogued weak source, within the 20 arcsec EP/FXT error circle (Ren et al., GCN 46142), is detected in our stacked r-band image at coordinates:
R.A. (J2000)= 5:27:24.31
Dec. (J2000)= -25:19:30.74
with an uncertainty of ~0.5 arcsec. Preliminary photometry for the source gives r = 23.86 +/- 0.25 mag, calibrated against nearby Legacy Survey DR10 stars and not corrected for Galactic extinction. The source is not present in the Legacy Survey r-band image, which is deeper than our NOT r-band image.
We thus think the source is likely the optical counterpart of EP261103a.