TITLE: GCN CIRCULAR NUMBER: 13132 SUBJECT: GRB 120327A: TAROT La Silla observatory optical decay DATE: 12/03/27 07:04:56 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We continue observations of GRB 120327A (trigger 518731) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. An optical decay alpha=1.3 (+/- 0.3) is deduced from the following observations: No filter: start end Rmag dmag filter (sec) (sec) 1944.2 2234.6 16.96 0.17 CR 2387.2 3159.2 17.31 0.19 CR 3169.5 3938.0 17.81 0.09 CR 4156.0 4916.2 18.03 0.17 CR 4926.5 6102.7 18.84 0.13 CR R filter: start end Rmag dmag filter (sec) (sec) 2767.6 3539.5 17.65 0.09 R 3948.0 4716.3 18.34 0.32 R 5116.5 7072.8 18.56 0.17 R 7472.9 10018.6 18.84 0.09 R Photometry is relative to the star NOMAD1 0605-0398765: (ra,dec) J2000 = (246.8438328,-29.4187269) R=14.930. Magnitudes are not corrected for galactic dust extinction. This message may be cited.