Sylvie Vauclair Laboratoire d’Astrophysique de Toulouse-Tarbes, CNRS,
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Transcript of Sylvie Vauclair Laboratoire d’Astrophysique de Toulouse-Tarbes, CNRS,
Sylvie VauclairLaboratoire d’Astrophysique de Toulouse-Tarbes, CNRS,Université de Toulouse, Institut universitaire de France
SONG Beijing meeting, March-April 2010
Precise modelling and asteroseismologyof exoplanet-host stars.
Why bothering about asteroseismologywhen studying exoplanets?
1) Same instruments, same observations, different time scales
2) Some people’s noise is other people’s signal
3) Obtain precise values of the parameters of exoplanets hosts stars
4) Links between asteroseismology and planets discoveries
SOPHIE OHP, T193August 2007
Richard, Michaud, Richer, ApJ 558, 391, 2001 (precise computations, OPAL)
More recently:Théado, Vauclair, Alecian, Leblanc, ApJ 704, 1262, 2009 (SVP approximation, OP)
1.5 Msun
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
log 1.7 Msun
1.7 Msun
many applications: SPB/Ceph, sdB, Dor, etc.
119 planet-host stars (dashed) ; 94 comparison stars (solid)
Exoplanets host stars
22 planet-host stars in binary systems (solid) ; dashed : single planet-host stars
Santos et al. 2005
Santos et al 2003
But!!!
heavy elements and… problem of Y
Pepe et al. 2007, A&A, 462, 769
Mu Arae
Bouchy, Bazot, Santos, Vauclair, Sosnowska 2005
43 detected modes , l = 0 to 3
AraeHD 160691
Soriano & Vauclair , A&A 2010
1.06 Msun
1.20 Msun
1.15 Msun
1.10 Msun
L/Ls
un
Soriano et al 2010 Arae
[Fe/H] = 0.29 [Fe/H] = 0.32 1.06 1.06
1.06 1.06
1.12 1.12
1.18
1.20
1.14
1.20
1.24
1.16
Mu Arae
model OM1, Yg, 1.10 Msun, 6.3 Gyr, [Fe/H]=0.32
Model with overshooting, ov = 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…
… and best models
( 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)
(Chereul et al 1999 ; Chereul and Grenon 2000) Hor belongs to the Hyades stream
Conclusions:waiting for SONGmuch work for future students!