{
  "eventType": [
    "X-ray Transient",
    "Optical Transient"
  ],
  "circularId": 45831,
  "eventId": "EP261006a",
  "submittedHow": "web",
  "format": "text/markdown",
  "submitter": "Rob Eyles-Ferris at U of Leicester <raje1@leicester.ac.uk>",
  "body": "R. A. J. Eyles-Ferris (Leicester), D. B. Malesani (DAWN/NBI and Radboud), G. Corcoran (UCD), J. A. Quirola-Vasquez (Radboud), P. G. Jonker (Radboud), and A. J. Levan (Radboud and Warwick) report on behalf of a larger collaboration:\n\nWe observed the field of the fast X-ray transient EP261006a (Lao et al., GCN 45826) with the Liverpool Telescope (LT) and the Nordic Optical Telescope (NOT) equipped with the IO:O and ALFOSC imagers, respectively. Observations started at 2026-10-06 23:26:24 UT (LT) and 2026-10-07 00:26:37 (NOT).\n\nIn image subtractions using Pan-STARRS templates, we identify a clear residual spatially consistent with the nucleus of the galaxy Gaia DR3 2587044864659595392. The location is also consistent with the EP-FXT localisation of the transient (GCN 45826). This residual is seen in all our images and we summarise our host-subtracted photometry below.\n\n| t_mid - t0 (hrs) | Telescope | Filter | Exposure time (s) | AB magnitude |\n| ------------- | --------- | ------ | ---------------- | ------------ |\n| 5.56 | LT | r | 6x150 | 20.22 +/- 0.03 |\n| 5.85 | LT | i | 6x150 | 20.78 +/- 0.05 |\n| 6.11 | LT | z | 5x150 | 20.59 +/- 0.07 |\n| 6.75 | NOT | r | 5x180 | 19.83 +/- 0.03 |\n\nWe note the rise in r-band brightness. Our magnitudes are calibrated to Pan-STARRS and not corrected for Galactic extinction. The blue r - i colour and nuclear location of EP261006a are consistent with the tentative classification as a TDE.\n",
  "subject": "EP261006a: LT and NOT discovery of an optical counterpart",
  "createdOn": 1791367591066
}