期刊
ASTRONOMY & ASTROPHYSICS
卷 542, 期 -, 页码 -出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201218835
关键词
stars: AGB and post-AGB; binaries: general; binaries: spectroscopic; stars: chemically peculiar; stars: evolution; stars: abundances
资金
- Fund for Scientific Research of Flanders (FWO), Belgium
- Research Council of K.U. Leuven, Belgium
- Fonds National Recherches Scientific (FNRS), Belgium
- Royal Observatory of Belgium
- Observatoire de Geneve, Switzerland
- Thuringer Landessternwarte Tautenburg, Germany
- Research Council of K.U. Leuven [GOA/2008/04]
- Scientific Fund of Flanders (FWO) [G.0703.08, G.0470.07]
- National Science Foundation [AST 1009974]
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1009974] Funding Source: National Science Foundation
Aims. We focus here on one particular and poorly studied object, IRAS 11472-0800. It is a highly evolved post-asymptotic giant branch (post-AGB) star of spectral type F, with a large infrared excess produced by thermal emission of circumstellar dust. Methods. We deployed a multi-wavelength study that includes the analyses of optical and IR spectra as well as a variability study based on photometric and spectroscopic time-series. Results. The spectral energy distribution (SED) properties as well as the highly processed silicate N-band emission show that the dust in IRAS 11472-0800 is likely trapped in a stable disc. The energetics of the SED and the colour variability show that our viewing angle is close to edge-on and that the optical flux is dominated by scattered light. With photospheric abundances of [Fe/H] = -2.7 and [Sc/H] = -4.2, we discovered that IRAS 11472-0800 is one of the most chemically-depleted objects known to date. Moreover, IRAS 11472-0800 is a pulsating star with a period of 31.16 days and a peak-to-peak amplitude of 0.6 mag in V. The radial velocity variability is strongly influenced by the pulsations, but the significant cycle-to-cycle variability is systematic on a longer time scale, which we interpret as evidence for binary motion. Conclusions. We conclude that IRAS 11472-0800 is a pulsating binary star surrounded by a circumbinary disc. The line-of-sight towards the object lies close to the orbital plane, therefore the optical light is dominated by scattered light. IRAS 11472-0800 is one of the most chemically-depleted objects known so far and links the dusty RV Tauri stars to the non-pulsating class of strongly depleted objects.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据