Spectral analysis of the He-enriched sdO-star HD 127493 [SSA]

http://arxiv.org/abs/1801.06350


The bright sdO star HD 127493 is known to be of mixed H/He composition and excellent archival spectra covering both optical and ultraviolet ranges are available. UV spectra play a key role as they give access to many chemical species that do not show spectral lines in the optical, such as iron and nickel. This encouraged the quantitative spectral analysis of this prototypical mixed H/He composition sdO star. We determined atmospheric parameters for HD 127493 in addition to the abundance of C, N, O, Si, S, Fe, and Ni in the atmosphere using non-LTE model atmospheres calculated with TLUSTY/SYNSPEC. A comparison between the parallax distance measured by Hipparcos and the derived spectroscopic distance indicate that the derived atmospheric parameters are realistic. From our metal abundance analysis, we find a strong CNO signature and enrichment in iron and nickel.

Read this paper on arXiv…

M. Dorsch, M. Latour and U. Heber
Mon, 22 Jan 2018
50/52

Comments: 7 pages, 5 figures, to be part of the Eighth Meeting on Hot Subdwarf Stars (sdob8) proceedings