EDP Sciences
Free Access
Volume 386, Number 2, May I 2002
Page(s) 504 - 516
Section Formation, structure and evolution of stars
DOI https://doi.org/10.1051/0004-6361:20020209
Published online 15 May 2002

A&A 386, 504-516 (2002)
DOI: 10.1051/0004-6361:20020209

RU Cen and SX Cen: Two strongly depleted RV Tauri stars in binary systems

The RV Tauri photometric b phenomenon and binarity
T. Maas, H. Van Winckel and C. Waelkens

Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium

(Received 11 September 2001 / Accepted 6 February 2002)

We present a chemical abundance analysis on the basis of high signal-to-noise and high-resolution ( $\lambda/\Delta\lambda\sim 48\,000$) optical spectra of two RV Tauri stars RU Cen and SX Cen. With an $\rm [Fe/H] = -1.9$ and a $\rm [Zn/Fe] = +0.9$ for RU Cen and a $\rm [Fe/H] = -1.1$ and a $\rm [Zn/Fe] = +0.6$ for SX Cen, both stars of spectroscopic class B display strong depletion of refractory elements in their photospheres. Our CORALIE radial velocity measurements prove the stars to be members of binary systems and a detailed construction of the spectral energy distribution indicate the presence of a large amount of hot circumstellar dust. Moreover, the orbital period of SX Cen of around 600 days is similar to the published period of mean magnitude variation in the light curve (RV Tauri phomometric class b phenomenon). All these observations indicate the presence of a stable circumbinary disk in the objects and strengthen the model that this is a necessary condition for the depletion process to take place.

Key words: stars: abundances -- stars: AGB and post-AGB -- stars: evolution -- stars: individual: RU Cen -- stars: individual: SX Cen -- stars: individual: RV Tauri

Offprint request: T. Maas, Thomas.Maas@ster.kuleuven.ac.be

SIMBAD Objects

© ESO 2002

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.