The magnetic, basal, and radiative-equilibrium components in Mount Wilson Ca II H + K fluxes

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167561· OSTI ID:5509615

Schrijver, C J; Dobson, A K; Radick, R R ^[1]

---

1. National Solar Observatory, Sunspot, NM (USA)

Mount Wilson Ca II H + K flux measurements of cool dwarf stars are analyzed and compared with stellar Mg II h + k fluxes, variability amplitudes, rotation rates, and solar data. It is concluded that the Mount Wilson Ca II H + K fluxes comprise three principal parts: (1) a photospheric contribution in the line wings, (2) a basal chromospheric component that appears to be unrelated to stellar magnetic activity and is, therefore, possibly nonmagnetic in origin, and (3) a chromospheric component which is associated with magnetically active regions and the (quiet and active) network. The basal chromosphere appears to cover the entire surface of magnetically inactive stars. The basal Ca II H + K flux density for solar-type stars equals the average emission observed in the centers of solar supergranulation cells, where the magnetic flux density is small. 27 refs.

• OSTI ID: 5509615
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 341; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
ATMOSPHERES
CALCIUM
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
DWARF STARS
ELEMENTS
MAGNETIC FIELDS
MAGNETIC FLUX
METALS
MOTION
ROTATION
SPECTRA
STARS
STELLAR ATMOSPHERES