TITLE: GCN CIRCULAR NUMBER: 39156 SUBJECT: GRB 250205A: Liverpool Telescope optical counterpart candidate detection DATE: 25/02/05 22:53:06 GMT FROM: Ben Gompertz at U of Birmingham b.gompertz@bham.ac.uk

B. P. Gompertz (U. Birmingham), D. B. Malesani (DAWN/NBI and Radboud) and A. J. Levan (Radboud) report on behalf of a larger collaboration:

We initiated follow-up observations of GRB 250205A (Saccardi et al., GCN 39154) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 21:56:04, 32 minutes after the ECLAIRS trigger, and consisted of 5x120 s exposures in the SDSS r filter.

A new optical source, not present in archival PS1 imaging, is detected at RA = 07:34:02.64, Dec +32:22:18.79 (J2000). In a preliminary analysis, we measure an AB magnitude of r = 20.91 +/- 0.06, calibrated against nearby Pan-STARRS stars and not corrected for galactic extinction. Follow-up observations to assess the evolution of the candidate are encouraged.

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