{
  "eventId": "EP260119a",
  "submitter": "Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>",
  "body": "R. A. J. Eyles-Ferris (Leicester), J. A. Quirola-Vasquez (Radboud), G. Corcoran (UCD), D. B. Malesani (DAWN-NBI and Radboud), A. van Hoof (Radboud), A. Martin-Carrillo (UCD), P. G. Jonker (Radboud), A. J. Levan (Radboud and Warwick) report on behalf of a larger group:\n\nWe observed the field of the fast X-ray transient EP260119a (Jiang et al., GCN 43447; Cheng et al., GCN 43449) using an LCO 1m telescope located at the McDonald Observatory (Texas, USA) equipped with the SINISTRO instrument. A series of 3x300 s exposures was taken in each of the SDSS-r and SDSS-z filters, starting on 2026-01-19 at 09:40:45 UT (9.45 hr after the trigger).\n\nThe optical counterpart discovered by COLIBRÍ (Fortin et al., GCN 43450) is detected in our images, with magnitudes:\n\nr = 22.83 +- 0.33 (9.54 hr after trigger)\nz = 20.26 +- 0.13 (9.81 hr after trigger)\n\nThese values are in the AB system, are calibrated against the Pan-STARRS survey, and are not corrected for Galactic extinction. Our measurements confirm the red r-z color of the afterglow (Fortin et al., GCN 43450).\n\nNo host galaxy is detected in the r band in a stack of archival CFHT images, down to a limiting magnitude r > 24.5.\n",
  "createdOn": 1768827757486,
  "subject": "EP260119a: LCO optical observations",
  "circularId": 43452,
  "submittedHow": "web",
  "bibcode": "2026GCN.43452....1E",
  "format": "text/plain"
}