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Title: SOLAR CYCLE VARIATION IN SUN-AS-A-STAR Ca II 854.2 nm BISECTORS

Abstract

The bisector of the strong chromospheric Ca II 854.2 nm line has an inverse-C shape, the cause of which is not yet fully understood. We show that the amplitude of the bisector in Sun-as-a-star observations exhibits a solar cycle variation with smaller amplitudes during highest activity. The line core intensity is lower during solar minima while the part of the bisector most sensitive to the line core shows no systematic change with activity. Our results support the use of Ca II 854.2 nm bisectors in studying the relationship between convection and magnetic fields, not only in the Sun but in other stars as well.

Authors:
;  [1]
  1. National Solar Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States)
Publication Date:
OSTI Identifier:
21578251
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 736; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/736/2/114; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALCIUM; CHROMOSPHERE; CONVECTION; MAGNETIC FIELDS; SOLAR CYCLE; VARIATIONS; ALKALINE EARTH METALS; ATMOSPHERES; ELEMENTS; ENERGY TRANSFER; HEAT TRANSFER; MASS TRANSFER; METALS; SOLAR ATMOSPHERE; STELLAR ATMOSPHERES

Citation Formats

Pietarila, A., and Livingston, W.. SOLAR CYCLE VARIATION IN SUN-AS-A-STAR Ca II 854.2 nm BISECTORS. United States: N. p., 2011. Web. doi:10.1088/0004-637X/736/2/114.
Pietarila, A., & Livingston, W.. SOLAR CYCLE VARIATION IN SUN-AS-A-STAR Ca II 854.2 nm BISECTORS. United States. doi:10.1088/0004-637X/736/2/114.
Pietarila, A., and Livingston, W.. Mon . "SOLAR CYCLE VARIATION IN SUN-AS-A-STAR Ca II 854.2 nm BISECTORS". United States. doi:10.1088/0004-637X/736/2/114.
@article{osti_21578251,
title = {SOLAR CYCLE VARIATION IN SUN-AS-A-STAR Ca II 854.2 nm BISECTORS},
author = {Pietarila, A. and Livingston, W.},
abstractNote = {The bisector of the strong chromospheric Ca II 854.2 nm line has an inverse-C shape, the cause of which is not yet fully understood. We show that the amplitude of the bisector in Sun-as-a-star observations exhibits a solar cycle variation with smaller amplitudes during highest activity. The line core intensity is lower during solar minima while the part of the bisector most sensitive to the line core shows no systematic change with activity. Our results support the use of Ca II 854.2 nm bisectors in studying the relationship between convection and magnetic fields, not only in the Sun but in other stars as well.},
doi = {10.1088/0004-637X/736/2/114},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 736,
place = {United States},
year = {2011},
month = {8}
}