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Precise modelling and asteroseismology of exoplanet-host stars. Sylvie Vauclair Laboratoire d’Astrophysique de Toulouse-Tarbes, CNRS, Université de Toulouse, Institut universitaire de France. SONG Beijing meeting, March-April 2010. Why bothering about asteroseismology
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Precise modelling and asteroseismology of exoplanet-host stars. Sylvie Vauclair Laboratoire d’Astrophysique de Toulouse-Tarbes, CNRS, Université de Toulouse, Institut universitaire de France SONG Beijing meeting, March-April 2010
Why bothering about asteroseismology when studying exoplanets? • Same instruments, same observations, different time scales • Some people’s noise is other people’s signal • Obtain precise values of the parameters of exoplanets hosts stars • Links between asteroseismology and planets discoveries SOPHIE OHP, T193 August 2007
Richard, Michaud, Richer, ApJ 558, 391, 2001 (precise computations, OPAL) 1.5 Msun More recently: Théado, Vauclair, Alecian, Leblanc, ApJ 704, 1262, 2009 (SVP approximation, OP)
Double-diffusive convection (thermohaline) : c.f. S. Vauclair , ApJ 605, 874, 2004
Théado, Vauclair, Alecian, Leblanc, ApJ 704, 1262, 2009 Fe/Fe0 1.7 Msun
Exoplanets host stars 119 planet-host stars (dashed) ; 94 comparison stars (solid) 22 planet-host stars in binary systems (solid) ; dashed : single planet-host stars Santos et al. 2005
But!!! Santos et al 2003 heavyelements and… problem of Y
Mu Arae Pepe et al. 2007, A&A, 462, 769
m Arae HD 160691 43 detected modes , l = 0 to 3 Soriano & Vauclair , A&A 2010
1.10 Msun 1.15 Msun Soriano et al 2010 m Arae 1.20 Msun 1.06 Msun L/Lsun
1.06 [Fe/H] = 0.29 [Fe/H] = 0.32 1.06 1.18 1.20 1.24 1.20 1.12 1.12 1.16 1.14 1.06 1.06
model OM1, Yg, 1.10 Msun, 6.3 Gyr, [Fe/H]=0.32 Model with overshooting, aov = 0.20 For crossing points and negative small separations, see : Soriano, M., Vauclair, S. 2008, A&A, 488, 975
turning point of the l=2 waves: where Sl(rt) is the Lamb frequency:
iota Horologii : seismic analysis… ( For each metallicity, Teff of best model decreases for decreasing Y ) Vauclair et al., submitted to A&A Best seismic models Hyades (Lebreton et al. 2001) … and best models
(Chereul et al 1999 ; Chereul and Grenon 2000) • Hor belongs to the Hyades stream
Conclusions: waiting for SONG much work for future students!