Spectral analysis of M dwarfs
نویسندگان
چکیده
منابع مشابه
Near-Infrared Spectral Classification of late-M and L Dwarfs
We present near-infrared (1 to 2.5 μm) low-resolution spectroscopy of eleven ultracool dwarfs with spectral types ranging from M7 to L8. Combining our observations with data published previously by Leggett et al. (2001), we have measured equivalent widths for the strongest atomic features and constructed narrowband indices to gauge the strength of the strongest molecular features. Those measure...
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We have obtained infrared (1—2.5µm) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric parameters metallicity, effective temperature and radius are determined for the sample. We find good agreement between observation and theory except for known proble...
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We have found a dramatic change in the spectra of late-type M dwarfs at wavelengths shorter than 0.75μm. Comparisons with synthetic spectra illustrate that this change is well explained by the presence of dust. It thus seems that a substantial part of the long-standing discrepancies between late-type M dwarf models and observations arises from dust as recently proposed by Tsuji, Ohnaka & Aoki (...
متن کاملMetallicity determination of M dwarfs
Lindgren, S. 2017. Metallicity determination of M dwarfs. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1587. 46 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0127-3. M dwarfs constitute around 70% of all stars in the local Galaxy. Their multitude together with their long main-sequence lifetimes make them important for studies...
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The very hot, H-deecient PG 1159 stars are found in the post-AGB region of the Hertzsprung-Russell diagram. Most likely the \born-again" post-AGB scenario is valid for their evolution. It predicts a nal He-ash which brings back the star to the AGB, followed by a second (He burning) descent from the AGB where a superwind may take oo the entire H-rich and most of the He-rich envelope and lay bare...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1996
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/280.1.77