TITLE: GCN CIRCULAR NUMBER: 39114 SUBJECT: GRB 250129A: Liverpool Telescope observations suggest continued engine activity DATE: 25/02/01 13:22:21 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), R. Brivio (INAF-OAB) and A. J. Levan (Radboud) report on behalf of a larger collaboration: We initiated follow-up observations of GRB 250129A (Beardmore et al., GCN 39066) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations were taken across the nights of 2025-01-30 and 2025-01-31, consisting of 5x180 s exposures in each of the SDSS r and i filters. In a preliminary analysis, we measure the following AB magnitudes: t-t0(d) exp(s) filt mag error 2.06 900 r 20.29 0.04 2.93 900 r 20.40 0.05 Magnitudes are calibrated against nearby Pan-STARRS stars and are not corrected for galactic extinction. Our measurements indicate either minimal evolution between 2 and 3 days after trigger, or a continuation of the flaring behaviour observed during the first 24 hours, as noted by Belkin et al. (GCN 39072), Francile et al. (GCN 39075), Brivio et al. (GCN 39079), Zheng & Filippenko (GCN 39090), Antier et al. (GCN 39096), and Malesani et al. (GCN 39100). View this GCN Circular online at https://gcn.nasa.gov/circulars/39114. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...