GCN Circular 44897
Subject
EP260610b: Gemini North optical counterpart candidate
Event
Date
2026-06-10T16:54:45Z (a day ago)
From
Jonathan Quirola at Radboud University <jaquirola1990@gmail.com>
Via
Web form
A. J. Levan (Radboud & Warwick), J. Quirola-Vasquez (Radboud), R. A. J. Eyles-Ferris (Leicester), G. Corcoran (UCD), A. P. C. van Hoof (Radboud), P. G. Jonker (Radboud), D. B. Malesani (DAWN/NBI and Radboud), J. Chacón (PUC), H. Sun (NAO, CAS), F. E. Bauer (SSI and UTA) report on behalf of a larger collaboration:
We observed the localisation region of EP260610b (Wu et al. 2026, GCN 44895) with the Gemini North Telescope and the GMOS-N instrument on Mauna Kea, Hawaii, USA. Observations began at 13:36:51 UT on 10 June 2026 and consisted of 7 × 100 s exposures in the SDSS r band (~0.81 hr after T0) and 3 × 100 s exposures in the SDSS z band (~1.08 hr after T0).
By comparison with the Legacy Survey images, we identify a candidate optical counterpart at the following coordinates (J2000):
RA = 17:50:29.72
Dec = +46:32:10.6
Photometry performed on the stacked images yields r = 22.23 ± 0.03 and z = 22.19 ± 0.05 AB mag, calibrated against nearby stars from the Pan-STARRS catalog and not corrected for Galactic extinction.
We acknowledge the excellent support from the Gemini North staff in the execution of these challenging observations.