Atıf İçin Kopyala
Pavlovski K., Hummel C. A., Tkachenko A., Dervişoğlu A., Kayhan C., Zavala R. T., ...Daha Fazla
ASTRONOMY AND ASTROPHYSICS, cilt.658, sa.A92, ss.292-300, 2022 (SCI-Expanded)
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Yayın Türü:
Makale / Tam Makale
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Cilt numarası:
658
Sayı:
A92
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Basım Tarihi:
2022
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Doi Numarası:
10.1051/0004-6361/202142292
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Dergi Adı:
ASTRONOMY AND ASTROPHYSICS
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Derginin Tarandığı İndeksler:
Science Citation Index Expanded (SCI-EXPANDED)
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Sayfa Sayıları:
ss.292-300
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Akdeniz Üniversitesi Adresli:
Evet
Özet
Altough both components of the bright eclipsing binary α Dra having
been resolved using long baseline interferometry and the secondary component
shown to contribute some 15\% of the total flux, a spectroscopic detection of
the companion star was so far unsuccessful. To achieve our goals, we use a
combined data set from interferometry with the Navy Precision Optical
Interferometer (NPOI), photometry with the TESS space observatory, and
high-resolution spectroscopy with the HERMES fibre-fed spectrograph at the La
Palma observatory. We use the method of spectral disentangling to search for
the contribution of a companion star in the observed composite HERMES spectra,
to separate the spectral contributions of both components, and to determine
orbital elements of the α Dra system. TESS light curves are analysed in
an iterative fashion with spectroscopic inference of stellar atmospheric
parameters to determine fundamental stellar properties and their uncertainties.
Finally, NPOI interferometric measurements are used for determination of the
orbital parameters of the system and angular diameters of both binary
components. We report the first firm spectroscopic detection of the secondary
component in α Dra and deliver disentangled spectra of both binary
components. The inferred near-core mixing properties of both components do not
support a dependence of the convective core overshooting on the stellar mass.
At the same time, the α Dra system provides extra support to hypothesise
that the mass discrepancy in eclipsing spectroscopic double-lined binaries is
associated with inferior atmospheric modelling of intermediate- and high-mass
stars, and less so with the predictive power of stellar structure and evolution
models as to the amount of near-core mixing and mass of the convective core.
(abridged abstract)