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Surface lithium and cool spots

Published online by Cambridge University Press:  25 May 2016

F. C. Fekel
F. C. Fekel*
Affiliation:
Center for Automated Space Science and Center of Excellence in Information Systems Tennessee State University, Nashville, TN 37203, USA

Abstract

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Observations of lithium in sunspots resulted in the prediction of significant lithium equivalent-width variability in chromospherically active stars. Lithium observations of several types of active stars, such as pre-main-sequence stars and late-type dwarfs in very young clusters, whose members are assumed to be nearly coeval, as well as post-main-sequence objects, show a significant range of abundances. Thus, a number of researchers over the past decade have investigated star spots as the possible cause of the various observed lithium-abundance spreads. Observationally, some evidence has been found for lithium equivalent-width variations. Computed synthetic spectra indicate that under certain conditions significant variations should be detected, but such conditions are not often met except perhaps in the most active stars. While variations have been claimed for some T Tauri stars, simultaneous photometry and spectroscopy will be needed to explore the complex relation of spots and lithium-abundance variations. The fact that some post-main-sequence stars have lithium abundances similar to those of pre-main-sequence stars complicates the identification of isolated pre-main-sequence systems.

Type
Session III: “Photospheric Phenomena: Results”
Information
Symposium - International Astronomical Union , Volume 176: Stellar Surface Structure , 1996 , pp. 345 - 351
Copyright
Copyright © Kluwer 1996 

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