Circular polarization of the Ca II H and K lines in solar quiet and active regions

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185832· OSTI ID:6440045

Martinez Pillet, V; Garcia Lopez, R J; Del Toro Iniesta, J C; Rebolo, R; Vazquez, M ^[1]

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1. Instituto de Astrofisica de Canarias, La Laguna (Spain)

A representative set of profiles is presented for the Ca II H resonace line in Stokes V and I, for the quiet sun, plages, sunspot umbrae, and a flare, as well as one example of the Ca II K line in a sunspot penumbra. The degree of polarization is highest in the spots and zero in the quiet sun, within error limits. The V profile asymmetries are, however, highest in the flare. The spectra of the Ca II K line are used to obtain a linear relation between V(lambda) and -dI/d(lambda) and a value for B(parallel) of 820 + or - 40 G using the weak-field approximation. 25 refs.

• OSTI ID: 6440045
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 361; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
CALCIUM
ELEMENTS
EMISSION SPECTRA
MAGNETIC FIELDS
MAIN SEQUENCE STARS
METALS
POLARIZATION
SOLAR ACTIVITY
SOLAR FLARES
SPECTRA
STARS
STARSPOTS
STELLAR ACTIVITY
SUN
SUNSPOTS