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Description
We observed the tau Boo system with the HARPS-N spectrograph in order to test a new observational strategy aimed to jointly study asteroseismology, the planetary orbit and star-planet magnetic interaction. We collected high-cadence observations on 11 nearly consecutive nights, and for each night averaged the raw FITS files using dedicated software in order to obtain high S/N spectra to study the variation of the CaII H&K lines and radial velocity values free from stellar oscillations without losing this latter information. Specific software was written to build a new custom mask used to refine the RV determination with the HARPS-N pipeline and to perform the spectroscopic analysis. We updated the planetary ephemeris and proved the acceleration due to the stellar binary companion. The study of stellar activity variation suggests the presence of an high-latitude plage during the time span of our observations. The correlation between the chromospheric activity and the planetary orbital phase remains unclear. Solar-like oscillations are detected in the radial velocity time series: we estimate asteroseismic quantities finding good agreement with theoretical predictions. With the stellar model built we find for tau Boo an age of 0.9+/-0.5Gyr, and could further constrain the value of the stellar mass to 1.38+/-0.05M_{sun}_.
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