Detection of spectral variability of the optical component of the IR source IRAS 20508+2011
文献类型：期刊论文
| 作者 | Klochkova, VG; Panchuk, VE; Tavolzhanskaya, NS; Zhao, G
|
| 刊名 | ASTRONOMY REPORTS
 |
| 出版日期 | 2006-03-01 |
| 卷号 | 50期号:3页码:232-248 |
| 英文摘要 | Our high-resolution spectral observations have revealed variability of the optical spectrum of the cool Star identified with the IR source IRAS 20508+2011. We measured the equivalent widths Of numerous absorption lines of neutral atoms and ions at wavelengths 4300-7930 angstrom, along with the corresponding radial velocities. Over the four years of our observations, the radial velocity derived from photospheric absorption lines varied in the interval V-r. = 15-30 km/s. In the same period, the H alpha profile varied from being an intense bell-shaped emission line with a small amount of core absorption to displaying two-peaked emission with a central absorption feature below the Continuum level. At all but one epoch, the positions of the metallic photospheric lines were systematically shifted relative to the Ho, emission: Delta V-r = V-r(met) - V-r(H alpha, emis)approximate to -23 km/s. The Na D doublet displayed a complex profile with broad (half-width approximate to 120 km/s) emission and photospheric absorption, as well as an interstellar component. We used model atmospheres to determine the physical parameters and chemical composition of the star's atmosphere: T-eff = 4800 K, log g = 1.5, xi(t) = 4.0 km/s. The metallicity of the star differs little from the solar value: [Fe/H](.) = -0.36. We detected overabundances of oxygen [O/Fe](.) = +1.79 (with the ratio [C/O] approximate to -0.9), and alpha-process elements, as well as a deficit of heavy metals. The entire set of the star's parameters suggests that the optical component of WAS 20508+2011 is an "O-rich" AGB star with luminosity M-nu approximate to -3(m) that is close to its evolutionary transition to the post-AGB stage. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000237700000007 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/7209]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | 1.Special Astrophys Observ, Nizhnii Arkhyz 357147, Karachai Cherke, Russia 2.Chinese Acad Sci, Natl Astron Observ, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Klochkova, VG,Panchuk, VE,Tavolzhanskaya, NS,et al. Detection of spectral variability of the optical component of the IR source IRAS 20508+2011[J]. ASTRONOMY REPORTS,2006,50(3):232-248. |
| APA | Klochkova, VG,Panchuk, VE,Tavolzhanskaya, NS,&Zhao, G.(2006).Detection of spectral variability of the optical component of the IR source IRAS 20508+2011.ASTRONOMY REPORTS,50(3),232-248. |
| MLA | Klochkova, VG,et al."Detection of spectral variability of the optical component of the IR source IRAS 20508+2011".ASTRONOMY REPORTS 50.3(2006):232-248. |
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来源：国家天文台
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