Seminars at FGG

The HArps-n red Dwarf Exoplanet Survey (HADES). A spectroscopic analysis of the steady chromosphere of low-activity early-M dwarfs

Speaker: Gaetano Scandariato (Oss, di Palermo)

Date and time: 2017-09-22 11:30

While most of the planets discovered so far have been found orbiting around solar-type stars, low-mass stars have recently been recognized as a "shortcut" to glance into an exo-life laboratory. Currently, stellar activity is one of the most limiting factors for achieving the precision required to detect Earth-twins via the radial velocity method. Understanding the chromospheres of M dwarfs is crucial to solve this problem. In this contribution I present the spectroscopic analysis of the quiet early-M dwarfs currently being monitored in the framework of the HADES (HArps-n red Dwarf Exoplanet Survey) radial velocity survey. The wavelength range covered by the spectra allows us to analyze simultaneously the Call H&K doublet and the Balmer series, while the intensive follow up gives us a large number of spectra (up to ~100) for each targeted star. I present the study of the activity-rotation-stellar parameters and flux-flux relationships, and I also discuss the correlation of the Call H&K and Hα fluxes at low activity levels and the evolution timescales of chromospheric active regions.