Linking chromospheric activity and magnetic field properties for late-type dwarf stars
- Author(s)
- , E. L. Brown, S. V. Jeffers, S. C. Marsden, J. Morin, S. Boro Saikia, P. Petit, M. M. Jardine, V. See, A. A. Vidotto, M. W. Mengel, M. N. Dahlkemper
- Abstract
Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric logR'HK activity and the surface-averaged longitudinal magnetic field, Bl, giving the opportunity to probe the relationship between large-scale stellar magnetic fields and chromospheric manifestations of magnetism. We present logR'HK and/or Bl 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 logR'HK and mean log |Bl|, but for G stars the relationship may undergo a change between logR'HK ~ -4.4 and -4.8. The mean logR'HK shows a similar change with respect to the logR'HK 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 ≤ logR'HK ≤ -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 |Bl|, or the Bl and logR'HK 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.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Southern Queensland, Max Planck Institute for Solar System Research, University of Montpellier, University of Toulouse, University of St. Andrews, Science and Operations Department - Science Division (SCI-SC), University of Exeter, University of Dublin, Leiden University, Georg-August-Universität Göttingen, European Organization for Nuclear Research (CERN)
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 514
- Pages
- 4300-4319
- No. of pages
- 20
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stac1291
- Publication date
- 08-2022
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/19f906f6-3b07-4362-832f-8ef06ba2655d