Linking chromospheric activity and magnetic field properties for late-type dwarf stars

Abstract

Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric $\log R_{\mathrm{HK}}^{\prime }$ activity and the surface-averaged longitudinal magnetic field, $B_l$, giving the opportunity to probe the relationship between large-scale stellar magnetic fields and chromospheric manifestations of magnetism. We present $\log R_{\mathrm{HK}}^{\prime }$ and/or $B_l$ measurements for 954 mid-F to mid-M stars derived from spectropolarimetric observations contained within the PolarBase database. Our magnetically active sample complements previous stellar activity surveys that focus on inactive planet-search targets. We find a positive correlation between mean $\log R_{\mathrm{HK}}^{\prime }$ and mean $\log |B_l|$, but for G stars the relationship may undergo a change between $\log R_{\mathrm{HK}}^{\prime }\sim -4.4$ and $-4.8$. The mean $\log R_{\mathrm{HK}}^{\prime }$ shows a similar change with respect to the $\log R_{\mathrm{HK}}^{\prime }$ variability amplitude for intermediately-active G stars. We also combine our results with archival chromospheric activity data and published observations of large-scale magnetic field geometries derived using Zeeman Doppler Imaging. The chromospheric activity data indicate a slight under-density of late-F to early-K stars with $-4.75\le \log R_{\mathrm{HK}}^{\prime }\le -4.5$. This is not as prominent as the original Vaughan-Preston gap, and we do not detect similar under-populated regions in the distributions of the mean $|B_l|$, or the $B_l$ and $\log R_{\mathrm{HK}}^{\prime }$ variability amplitudes. Chromospheric activity, activity variability and toroidal field strength decrease on the main sequence as rotation slows. For G stars, the disappearance of dominant toroidal fields occurs at a similar chromospheric activity level as the change in the relationships between chromospheric activity, activity variability and mean field strength.

20 pages, 15 figures, 3 tables

References in corpus (28)

• The Gaia mission
• Modules for Experiments in Stellar Astrophysics (MESA)
• Constraining the Age-Activity Relation for Cool Stars: The SDSS DR5 Low-Mass Star Spectroscopic Sample
• Large-scale magnetic topologies of late M dwarfs
• Large-scale magnetic topologies of early M dwarfs
• Toroidal versus poloidal magnetic fields in Sun-like stars: a rotation threshold
• Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs
• TW Hydrae: evidence of stellar spots instead of a Hot Jupiter
• Patterns of photometric and chromospheric variation among Sun-like stars: A 20-year perspective
• Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence
• Magnetospheric accretion on the T Tauri star BP Tauri
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• Magnetic cycles of the planet-hosting star tauBootis
• The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr)
• Stellar chromospheric activity of 1,674 FGK stars from the AMBRE-HARPS sample I. A catalogue of homogeneous chromospheric activity
• The Sun is less active than other solar-like stars
• Spectropolarimetric observations of the transiting planetary system of the K dwarf HD 189733
• The connection between stellar activity cycles and magnetic field topology
• Estimating magnetic filling factors from Zeeman-Doppler magnetograms
• Modelling the magnetic activity & filtering radial velocity curves of young Suns: the weak-line T Tauri star LkCa 4
• Magnetic fields on young, moderately rotating Sun-like stars - I: HD~35296 and HD~29615
• Variable magnetic field geometry of the young sun HN Peg (HD 206860)
• Do non-dipolar magnetic fields contribute to spin-down torques?
• Magnetic fields on young, moderately rotating Sun-like stars II. EK Draconis (HD 129333)
• On the mass accretion rate and infrared excess in Herbig Ae/Be Stars
• The relation between stellar magnetic field geometry and chromospheric activity cycles I: The highly variable field of Epsilon Eridani at activity minimum
• Magnetic topologies of young suns: The weak-line T Tauri stars TWA 6 and TWA 8A
• Magnetic field and chromospheric activity evolution of HD75332: a rapid magnetic cycle in an F star without a hot Jupiter

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• Stellar Chromospheric Activity Database of Solar-like Stars Based on the LAMOST Low-Resolution Spectroscopic Survey: II. the bolometric and photospheric calibration
• A Spectroscopic Analysis of a Sample of K2 Planet-Host Stars: Stellar Parameters, Metallicities and Planetary Radii
• KOBE-1: The first planetary system from the KOBE survey. Two planets likely residing in the sub-Neptune mass regime around a late K-dwarf
• Multi-wavelength aperture polarimetry of debris disc host stars
• Four ages of rotating stars in the rotation--activity relationship and gyrochronology
• Stellar Characterization and a Chromospheric Activity Analysis of a K2 Sample of Planet-Hosting Stars
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• The SOL $\text{(Solar Origin and Life)}$ Project: Detailed characterization of candidates for the ZAMS and Subgiant stages