Asteroseismology of Procyon: Preliminary results from SARG

The F5 IV-V subgiant Procyon was observed over 6 nights with SARG at TNG. We took sequences of 10 s exposures with an average dead time in between of 127 s. In total, 956 spectra were collected with a typical signal-to-noise ratio ranging between 250-330. Data reduction was performed using IRAF tasks devoted to echelle spectra. Successively the modelling of the star plus iodine absorption spectra was performed by using AUSTRAL code (Endl et al. 2000, A&A, 362, 585) in order to obtain the radial velocities time series. The Scargle and Lomb modified periodogram (Lomb 1976, Ap&SS, 39, 447, Scargle 1982, ApJ, 263, 835) shows two prominent frequencies: ν1 = 0.2346 mHz and ν2 = 0.8387 mHz both with a significance level greater than 99% . Frequency ν2 corresponds to the 20 min period found by Brown et al. (1991 ApJ, 368, 599).