The Ca II H&K Rotation-Activity Relation in 53 mid-to-late type M-Dwarfs

Abstract

In the canonical theory of stellar magnetic dynamo, the tachocline in partially convective stars serves to arrange small-scale fields, generated by stochastic movement of plasma into a coherent large-scale field. Mid-to-late M-dwarfs, which are fully convective, show more magnetic activity than classical magnetic dymano theory predicts. However, mid-to-late M-dwarfs show tight correlations between rotation and magnetic activity, consistent with elements of classical dynamo theory. We use data from Magellan Inamori Kyocera Echelle (MIKE) Spectrograph to detail the relation between Ca II H\&K flux and rotation period for these low-mass stars. We measure $R_{HK}^{\prime }$ values for 53 spectroscopically identified M-dwarfs selected from the MEarth survey; these stars span spectral classes from M5.0 to M3.5 and have rotation periods ranging from hours to months. We present the rotation--activity relationship as traced through these data. We find power law and saturated regimes consistent to within one sigma of previously published results and observe a mass dependence in $R_{HK}^{\prime }$.

11 pages, 5 figures, 1 table

References in corpus (11)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• Generalized investigation of the rotation-activity relation: Favouring rotation period instead of Rossby number
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• Relation of X-ray activity and rotation in M dwarfs and predicted time-evolution of the X-ray luminosity
• Flare Rates, Rotation Periods. and Spectroscopic Activity Indicators of a Volume-Complete Sample of Mid-to-Late M dwarfs within 15 Parsecs
• Ca II H and K Chromospheric Emission Lines in Late K and M Dwarfs
• The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities
• The Rotation-Activity Correlations in K and M dwarfs. II. New constraints on the dynamo mechanisms in late-K and M dwarfs before and at the transition to complete convection

Cited by in corpus (6)

• A detailed analysis of the Gl 486 planetary system
• Further evidence of the link between activity and metallicity using the flaring properties of stars in the Kepler field
• Correlation between activity indicators: H$\alpha$ and Ca II lines in M-dwarf stars
• Contemporaneous Observations of $H\alpha$ Luminosities and Photometric Amplitudes for M Dwarfs
• Stellar Chromospheric Activity Database of Solar-like Stars Based on the LAMOST Low-Resolution Spectroscopic Survey: II. the bolometric and photospheric calibration
• The white-light superflares from cool stars in GWAC triggers