6533b7cefe1ef96bd1257aee
RESEARCH PRODUCT
The HADES RV Programme with HARPS-N@TNG. III. Flux-flux and activity-rotation relationships of early-M dwarfs
Jesus MaldonadoR. Zanmar SanchezIsabella PaganoA. F. LanzaGaetano ScandariatoR. G. GrattonAlessandro SozzettiGiuseppina MicelaMario DamassoAntonio MaggioKatia BiazzoGiampaolo PiottoGiampaolo PiottoRiccardo ClaudiSergio MessinaManuel PergerIgnasi RibasEmilio MolinariBeate StelzerA. Suárez MascareñoA. Suárez MascareñoRafael ReboloRafael ReboloGiuseppe LetoSilvano DesideraE. González ÁLvarezE. González ÁLvarezRosario CosentinoJ. I. González HernándezJ. I. González HernándezLaura Affersubject
Red dwarfAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesContext (language use)AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencessymbols.namesake0103 physical sciencesAstrophysics::Solar and Stellar Astrophysics010303 astronomy & astrophysicsSolar and Stellar Astrophysics (astro-ph.SR)Astrophysics::Galaxy AstrophysicsPhysics010308 nuclear & particles physicsStellar atmosphereBalmer seriesAstronomy and AstrophysicsEffective temperatureExoplanetRadial velocityStarsAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary SciencesymbolsAstrophysics::Earth and Planetary Astrophysicsdescription
(Abridged) Understanding stellar activity in M dwarfs is crucial for the physics of stellar atmospheres as well as for ongoing radial velocity exoplanet programmes. Despite the increasing interest in M dwarfs, our knowledge of the chromospheres of these stars is far from being complete. We aim to test whether the relations between activity, rotation, and stellar parameters and flux-flux relationships also hold for early-M dwarfs on the main-sequence. We analyse in an homogeneous and coherent way a well defined sample of 71 late-K/early-M dwarfs that are currently being observed in the framework of the HArps-n red Dwarf Exoplanet Survey (HADES). Rotational velocities are derived using the cross-correlation technique while emission flux excesses in the Ca II H & K and Balmer lines from Halpha up to Hepsilon are obtained by using the spectral subtraction technique. The relationships between the emission excesses and the stellar parameters are studied. Relations between pairs of fluxes of different chromospheric lines are also studied. We find that the strength of the chromospheric emission in the Ca II H & K and Balmer lines is roughly constant for stars in the M0-M3 spectral range. Our data suggest that a moderate but significant correlation between activity and rotation might be present as well as a hint of kinematically selected young stars showing higher levels of emission. We find our sample of M dwarfs to be complementary in terms of chromospheric and X-ray fluxes with those of the literature, extending the analysis of the flux-flux relationships to the very low flux domain. Our results agree with previous works suggesting that the activity-rotation-age relationship known to hold for solar-type stars also applies to early-M dwarfs. We also confirm previous findings that the field stars which deviate from the bulk of the empirical flux-flux relationships show evidence of youth.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-10-19 |