2008/07/23 by Bruce J. Hrivnak, Hans Van Winckel, H. Van Winckel +5 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Asymptotic giant branch #Circumbinary planet #Physics #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1088/0004-6256/136/4/1557
Machine readable files not included
arxiv created 2008/07/23 · openalex publication_date 2008/09/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The metal-poor post-asymptotic giant branch (AGB) star HD 46703 is shown to be a single-line spectroscopic binary with a period of 600 days, a high velocity of −94 km s −1 , and an orbital eccentricity of 0.3. Light-curve studies show that it also pulsates with a period of 29 days. High-resolution, high signal-to-noise spectra were used for a new abundance study. The atmospheric model determined is T eff = 6250 K, log g = 1.0, V t = 3.0 km s −1 , and a metal abundance of [M/H] = −1.5. A low carbon abundance and a lack of s-process element enhancement indicate that the star has not experienced a third dredge-up on the AGB. The sulfur and zinc abundances are high compared with iron, and the chemical abundances show a clear anti-correlation with condensation temperature. The abundance depletion pattern is similar to that seen in other post-AGB binaries, and, like them, is attributed to the chemical fractionation of refractory elements onto dust stored in a circumbinary disk and the re-accretion of volatiles in the stellar atmosphere. The infrared excess is small but the excess energy distribution is very similar to what can be expected from a disk. HD 46703 joins the growing list of depleted, post-AGB stars which are likely surrounded by a dusty and stable circumbinary disk.