A MODEL FOR INTERFACE DYNAMOS IN LATE K AND EARLY M DWARFS

Journal Article · Thu Sep 10 00:00:00 EDT 2015 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/810/2/L18· OSTI ID:22518893

Mullan, D. J.; MacDonald, J. ^[1]

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1. Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

Measurements of the equivalent width EW(CaK) of emission in the Ca ii K line have been obtained by Houdebine et al. for stars with spectral types from dK5 to dM4. In order to explain the observed variations of EW(CaK) with spectral sub-type, we propose a quantitative model of interface dynamos in low-mass stars. Our model leads to surface field strengths B{sub s} which turn out to be essentially linearly proportional to EW(CaK). This result is reminiscent of the Sun, where Skumanich et al. found that the intensity of CaK emission in solar active regions is linearly proportional to the local field strength.

• OSTI ID: 22518893
• Journal Information: Astrophysical Journal Letters, Vol. 810, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CALCIUM
EMISSION SPECTRA
INTERFACES
MAGNETIC FIELDS
MASS
SUN
VARIATIONS