Element Abundances in the Upper Atmospheres of the Sun and Stars: Update of Observational Results
- 1 February 2000
- journal article
- Published by IOP Publishing in Physica Scripta
- Vol. 61 (2) , 222-252
- https://doi.org/10.1238/physica.regular.061a00222
Abstract
We review observational progress in the determination of element abundances in the solar corona, largely due to the new capabilities offered by the instrumentation on the SOHO satellite. Many new facets to coronal abundance anomalies with respect to the photosphere are revealed. This includes new results on the FIP (First Ionization Potential) Effect, whereby elements with FIP < 10 eV are enriched in the corona by a factor ~4 with respect to the photosphere, and the first evidence for gravitational settling of heavy elements in the corona. Advances in EUV and x-ray astronomy instrumentation have also yielded the first spectra of stellar coronae of sufficient quality to allow element abundance measurements. We survey these new results and compare the various stellar cases to the solar corona.Keywords
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