GCN Circular 46148
Subject
EP261103a: NTT optical observation
Event
Date
2026-11-04T12:38:05Z (a day ago)
From
Agnes van Hoof at Radboud University <agnes.vanhoof@ru.nl>
Via
Web form
G. Corcoran (UCD), A.P.C. van Hoof (Radboud), A. Martin-Carrillo (UCD), J. Sanchez-Sierras (Radboud), P. G. Jonker (Radboud), H. C. I. Wichern (DTU Space), S. de Wet (DTU Space) report on behalf of a larger collaboration:
We observed the field of the Einstein Probe fast X-ray transient EP261103a (Ren et al., GCN 46142) with the New Technology Telescope (NTT) equipped with the EFOSC2 instrument. Observations consisted of a sequence of 9 x 200s exposures in both the Gunn r band and Gunn z band. The r-band observations started on 2026-11-04 4:58:46 UT (8.67 h after the EP/WXT trigger) and the z-band observations started on 2026-11-04 5:34:36 UT (9.3 h after the EP/WXT trigger).
We detect the optical counterpart (Jiang et al., GCN 46143; Ma et al., GCN 46145) in our r-band image. We obtain the following photometry on our stacked images:
r = 24.10 +/- 0.13
z > 23 (3-sigma)
Magnitudes are in the AB system, calibrated against PanSTARRS and not corrected for Galactic extinction.