Optical Interferometry of early-type stars with PAVO@CHARA. I. Fundamental stellar properties
| Autor: | Peter G. Tuthill, Vicente Maestro, Gail Schaefer, Jane Robertson, Timothy R. White, John D. Monnier, Michael J. Ireland, T. ten Brummelaar, Yitping Kok, Xiao Che, Daniel Huber |
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| Rok vydání: | 2013 |
| Předmět: |
Physics
010308 nuclear & particles physics Stellar atmosphere Astronomy FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Type (model theory) Effective temperature Stellar classification Giant star Surface gravity 01 natural sciences Luminosity Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.1306.5937 |
| Popis: | We present interferometric observations of 7 main-sequence and 3 giant stars with spectral types from B2 to F6 using the PAVO beam combiner at the CHARA array. We have directly determined the angular diameters for these objects with an average precision of 2.3%. We have also computed bolometric fluxes using available photometry in the visible and infrared wavelengths, as well as space-based ultraviolet spectroscopy. Combined with precise \textit{Hipparcos} parallaxes, we have derived a set of fundamental stellar properties including linear radius, luminosity and effective temperature. Fitting the latter to computed isochrone models, we have inferred masses and ages of the stars. The effective temperatures obtained are in good agreement (at a 3% level) with nearly-independent temperature estimations from spectroscopy. They validate recent sixth-order polynomial (B-V)-$T_\mathrm{eff}$ empirical relations \citep{Boyajian2012a}, but suggest that a more conservative third-order solution \citep{vanBelle2009} could adequately describe the (V-K)-$T_\mathrm{eff}$ relation for main-sequence stars of spectral type A0 and later. Finally, we have compared mass values obtained combining surface gravity with inferred stellar radius (\textit{gravity mass}) and as a result of the comparison of computed luminosity and temperature values with stellar evolutionary models (\textit{isochrone mass}). The strong discrepancy between isochrone and gravity mass obtained for one of the observed stars, $\gamma$\,Lyr, suggests that determination of the stellar atmosphere parameters should be revised. Comment: 13 pages, 9 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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