High precision radial velocity monitoring of Arcturus with SONG: Results of the 3-year continuous campaign
Pere L. Pallé, T. Roca Cortés, F. Grundahl, C. Regulo, , H. Kjeldsen, R.A. García, J. F. Pérez Hernández, S. Mathur, M.A. Andersen and the SONG Team

Abstract

The successful operation of the first robotic node of the SONG network at the Observatorio del Teide, has allowed an unprecedented observing campaign (2016-2018) of the high-precision RV of the ”reference” star Arcturus (\alpha Boo): an evolved red giant similar to our future Sun. Although this star has been observed over the past decades, many basics questions remain open concerning its nature, location at the H-R diagram and global parameters (mass, age) as a consequence of the lack of a proper asteroseismic characterization. The analysis of the exquisite data gathered (RV precision < 1.2 m/s per point), has allowed to firmly stablish its long-term variation (period \sim 170 days and amplitude \sim 200 m/s) and the analysis of its eigenmodes spectrum (periods of about 2-days) should allow its proper asteroseismic characterization.
In this contribution, the current state of the analysis and preliminary results and inferences will be presented.