Bibcode
Appourchaux, T.; Antia, H. M.; Ball, W.; Creevey, O.; Lebreton, Y.; Verma, K.; Vorontsov, S.; Campante, T. L.; Davies, G. R.; Gaulme, P.; Régulo, C.; Horch, E.; Howell, S.; Everett, M.; Ciardi, D.; Fossati, L.; Miglio, A.; Montalbán, J.; Chaplin, W. J.; García, R. A.; Gizon, L.
Bibliographical reference
Astronomy and Astrophysics, Volume 582, id.A25, 19 pp.
Advertised on:
10
2015
Journal
Citations
41
Refereed citations
37
Description
Context. Solar-like oscillations have been observed by Kepler and CoRoT
in many solar-type stars, thereby providing a way to probe stars using
asteroseismology. Aims: The derivation of stellar parameters has
usually been done with single stars. The aim of the paper is to derive
the stellar parameters of a double-star system (HIP 93511), for which an
interferometric orbit has been observed along with asteroseismic
measurements. Methods: We used a time series of nearly two years
of data for the double star to detect the two oscillation-mode envelopes
that appear in the power spectrum. Using a new scaling relation based on
luminosity, we derived the radius and mass of each star. We derived the
age of each star using two proxies: one based upon the large frequency
separation and a new one based upon the small frequency separation.
Using stellar modelling, the mode frequencies allowed us to derive the
radius, the mass, and the age of each component. In addition, speckle
interferometry performed since 2006 has enabled us to recover the orbit
of the system and the total mass of the system. Results: From the
determination of the orbit, the total mass of the system is
2.34-0.33+0.45 M⊙. The total
seismic mass using scaling relations is 2.47 ± 0.07
M⊙. The seismic age derived using the new proxy based
upon the small frequency separation is 3.5 ± 0.3 Gyr. Based on
stellar modelling, the mean common age of the system is 2.7-3.9 Gyr. The
mean total seismic mass of the system is 2.34-2.53 M⊙
consistent with what we determined independently with the orbit. The
stellar models provide the mean radius, mass, and age of the stars as
RA = 1.82-1.87R⊙, MA = 1.25-1.39
M⊙, AgeA = 2.6-3.5 Gyr; RB =
1.22-1.25 R⊙, MB = 1.08-1.14
M⊙, AgeB = 3.35-4.21 Gyr. The models provide
two sets of values for Star A: [1.25-1.27] M⊙ and
[1.34-1.39] M⊙. We detect a convective core in Star A,
while Star B does not have any. For the metallicity of the binary system
of Z ≈ 0.02, we set the limit between stars having a convective core
in the range [1.14-1.25] M⊙.
Appendices are available in electronic form at http://www.aanda.org
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