English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  The crucial role of surface magnetic fields for stellar dynamos: ϵ Eridani, 61 Cygni A, and the Sun

Jeffers, S. V., Cameron, R. H., Marsden, S. C., Boro Saikia, S., Folsom, C. P., Jardine, M. M., et al. (2022). The crucial role of surface magnetic fields for stellar dynamos: ϵ Eridani, 61 Cygni A, and the Sun. Astronomy and Astrophysics, 661, A152. doi:10.1051/0004-6361/202142202.

Item is

Files

show Files

Locators

show
hide
Description:
-
OA-Status:

Creators

show
hide
 Creators:
Jeffers, S. V.1, Author           
Cameron, R. H.1, 2, Author           
Marsden, S. C., Author
Boro Saikia, S., Author
Folsom, C. P., Author
Jardine, M. M., Author
Morin, J.3, Author           
Petit, P.4, Author           
See, V., Author
Vidotto, A. A., Author
Wolter, U., Author
Mittag, M., Author
Affiliations:
1Department Solar and Stellar Interiors, Max Planck Institute for Solar System Research, Max Planck Society, ou_1832287              
2Department Sun and Heliosphere, Max Planck Institute for Solar System Research, Max Planck Society, ou_1832287              
3Max Planck Institute of Molecular Cell Biology and Genetics, Max Planck Society, ou_2340692              
4MPS General, Max Planck Institute for Solar System Research, Max Planck Society, ou_1832292              

Content

show
hide
Free keywords: stars: activity; Sun: activity; stars: individual: 61 Cygni A; stars: individual: ϵ Eridani; stars: magnetic field; Astrophysics - Solar and Stellar Astrophysics
 Abstract: Cool main-sequence stars, such as the Sun, have magnetic fields which are generated by an internal dynamo mechanism. In the Sun, the dynamo mechanism produces a balance between the amounts of magnetic flux generated and lost over the Sun's 11-year activity cycle and it is visible in the Sun's different atmospheric layers using multi-wavelength observations. We used the same observational diagnostics, spanning several decades, to probe the emergence of magnetic flux on the two close by, active- and low-mass K dwarfs: 61 Cygni A and ϵ Eridani. Our results show that 61 Cygni A follows the Solar dynamo with a regular cycle at all wavelengths, while ϵ Eridani represents a more extreme level of the Solar dynamo, while also showing strong Solar-like characteristics. For the first time we show magnetic butterfly diagrams for stars other than the Sun. For the two K stars and the Sun, the rate at which the toroidal field is generated from surface poloidal field is similar to the rate at which toroidal flux is lost through flux emergence. This suggests that the surface field plays a crucial role in the dynamos of all three stars. Finally, for ϵ Eridani, we show that the two chromospheric cycle periods, of ∼3 and ∼13 years, correspond to two superimposed magnetic cycles. <P />The spectropolarimetic data are available from the Polarbase data archive: <A href="http://polarbase.irap.omp.eu/">http://polarbase.irap.omp.eu/</A>.

Details

show
hide
Language(s):
 Dates: 2022
 Publication Status: Issued
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1051/0004-6361/202142202
ISSN: 0004-6361
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Astronomy and Astrophysics
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 661 Sequence Number: - Start / End Page: A152 Identifier: -