English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present in this paper a study on the peculiar supergiant HD172481. Itsspectral type (F2Ia), high galactic latitude (b=-10.37), circumstellar dust,high radial velocity and moderate metal deficiency ([Fe/H]=-0.55) confirm thepost-AGB character of this object. A detailed chemical analysis shows slightbut real s-process overabundances, however no CNO-enhancement was detected.Furthermore, the spectral energy distribution and the TiO bands in the red partof the spectrum reveal a red luminous companion. The luminosity ratio of thehot F type component and this cool M type companion L(F)/L(M) is derived for areddening of E(B-V)=0.44 (L(F)/L(M)=1.8) and indicates that the companion mustalso be strongly evolved and probably evolving along the AGB. Neither ourphotometric data-set, nor our radial velocity monitoring show evidence fororbital variability which may indicate that the period is too large for directbinary interaction. Most interestingly, a strong lithium resonance line isdetected, which yields an abundance of log(Li)=3.6. Several explanations forthis large lithium content are explored.Comment: 11 pages, 9 figures, accepted for publication in Astronomy and  Astrophysic

HD 172481: A super lithium-rich metal-deficient post-AGB binary with a red AGB companion