TY - JOUR
T1 - A seismic and gravitationally bound double star observed by Kepler
T2 - Implication for the presence of a convective core
AU - Appourchaux, T.
AU - Antia, H. M.
AU - Ball, W.
AU - Creevey, O.
AU - Lebreton, Y.
AU - Verma, K.
AU - Vorontsov, S.
AU - Campante, T. L.
AU - Davies, G. R.
AU - Gaulme, P.
AU - Régulo, C.
AU - Horch, E.
AU - Howell, S.
AU - Everett, M.
AU - Ciardi, D.
AU - Fossati, L.
AU - Miglio, A.
AU - Montalbán, J.
AU - Chaplin, W. J.
AU - García, R. A.
AU - Gizon, L.
N1 - Funding Information:
T.A. gratefully acknowledges the financial support of the Centre National d’Etudes Spatiales (CNES) under a PLATO grant. T.L.C., W.J.C., and G.R.D. acknowledge financial support from the UK Science and Technology Facilities Council (STFC). W.B. and L.G. acknowledge support from the Deutsche Forschungsgemeinschaft SFB 963 “Astrophysical Flow Instabilities and Turbulence” (Project A18). L.G. acknowledges research funding from the Center for Space Science, NYU Abu Dhabi Institute, UAE. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation. We are indebted to Ian Roxburgh for extensively commenting on the paper and for his timely contribution. We are grateful to Sébastien Salmon for commenting on an earlier version of the paper. We are also indebted to Georges Herriman for silently accepting to use the name Krazy and Ignatz for these two stars. We are grateful to the anonymous referee for the constructive and useful comments.
PY - 2015/10/1
Y1 - 2015/10/1
N2 - 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 (HIP93511), 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⊙.
AB - 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 (HIP93511), 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⊙.
KW - asteroseismology
KW - astrometry
KW - binaries: general
KW - stars: evolution
KW - stars: solar-type
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U2 - 10.1051/0004-6361/201526610
DO - 10.1051/0004-6361/201526610
M3 - Article
AN - SCOPUS:84942741254
VL - 582
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
SN - 0004-6361
M1 - A25
ER -