TITLE: GCN CIRCULAR NUMBER: 17243 SUBJECT: GRB 141225A: TAROT Calern observatory optical observations DATE: 14/12/27 00:45:35 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A. (IRAP-CNRS-OMP), Gendre B. (IRAP-CNRS-OMP), Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 141225A detected by SWIFT (trigger 513505) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 8.2 min after the GRB trigger. The elevation of the field increased from 50 degrees above horizon and weather conditions were good. We co-added a series of exposures to measure the optical afterglow discovered by Gorosabel et al. (GCNC 17230): Tstart Tend (sec) (sec) Rmag +/- 496 907 18.8 0.3 918 1315 19.0 0.3 1327 1728 19.9 0.5 The afterglow is no longer detected in the next images. Magnitudes were estimated using USNO-B1 star USNO-B1 1237-0186662 (R.A.=138.789, Dec=+33.797) as Sonbas et al. (GCNC 17240). Magnitudes are not corrected for galactic dust extinction.