TITLE: GCN CIRCULAR NUMBER: 46143 SUBJECT: EP261103a: NOT optical counterpart candidate DATE: 26/11/04 05:13:44 GMT FROM: sqjiang at NAOC 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.