The Ne/O abundance ratio in the quiet Sun

Abstract

Context: .
Aims: .To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio.
Methods: .An emission measure method applied to extreme ultraviolet emission lines of Ne iv-vi and O iii-v ions observed by the Coronal Diagnostic Spectrometer on the SOHO satellite.
Results: .The average Ne/O abundance ratio in supergranule cell centre regions is 0.18± 0.05, while in supergranule network regions is 0.16± 0.04. A photospheric Ne/O ratio of 0.17± 0.05 is suggested, in good agreement with the most recent compilation of solar photospheric abundances, but discrepant with a recent Ne/O ratio derived from stellar X-ray spectra and revised neon abundances suggested from solar interior models.
Conclusions: .