The Ne/O abundance ratio in the quiet Sun

Aims: To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio. Method: 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.