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Current open issues in probing interiors of solar-like oscillating main sequence stars MJ Goupil, Y. Lebreton Paris Observatory J.P. Marques, R. Samadi, S. Talon ,J.Provost, S. Deheuvels, K. Belkacem, O. Benomar, F. Baudin, J. Ballot, B.Mosser T. Corbard, D. Reese, O. Creevey 1 Outline I The Sun Reviews: Basu, Antia 2008, Christensen-Dalsgaard, 2009; Turck Chieze et al , 2010 Major open issues From the Sun to stars II Solar like oscillating MS stars Open issues illustrated with CoRoT stars: HD49933, HD181420, HD42385 ground based observed HD208 Kepler data 2 A tout seigneur tout honneur, Noblesse oblige The Sun Solar constraints • Luminosity, GM⊙, R, age, surface abundances (Z/X)s • Seismic constrains From inversion of a large set of mode frequencies Found to be enough independent of the reference model -base of the upper convective zone -surface helium abundance -ionization regions through -sound speed profile : seismic solar model -rotation profile rbzc Ys 1 c(r ) (r,) 3 The Sun Major challenges and open issues in the solar case - Input parameters: surface abundances ? - Interior : sound speed : origin of the discrepancy below the convection zone Rotation profile Near surface layers - Probing the core - Mode physics : line widths and amplitudes convection-pulsation interaction 4 The Sun 1- Initial abundances: the solar mixture 1993-2010: several revisions of the photospheric solar mixture 2003: 3D model atmospheres + NLTE effects + improved atomic data ➥ decrease of C, N, O, Ne, Ar and (Z/X) Z/X GN93 GS98 AGS05 AGS09 Lod09 Caff10 0.0245 0.0229 0.0165 0.0181 0.0191 0.0209 5 The Sun 1- Initial abundances: the solar mixture 1993-2010: several revisions of the photospheric solar mixture 2003: 3D model atmospheres + NLTE effects + improved atomic data ➥ decrease of C, N, O, Ne, Ar and (Z/X) Z/X GN93 GS98 AGS05 AGS09 Lod09 Caff10 0.0245 0.0229 0.0165 0.0181 0.0191 0.0209 2009-2010 •Internal consistency of abundance determination from different ionisation levels of a given element •Consensus between independent determinations Grevesse & Noels 93, Grevesse & Sauval 1998, Asplund et al. 05, Asplund & al 09, Lodders et al. 09, Caffau et al 10 6 The Sun 1 Initial abundances: the solar mixture 7 The Sun 1 Initial abundances: the solar mixture 8 The Sun 1 Initial abundances: the solar mixture 9 The sun INPUT PHYSICS microscopic: Nuclear reactions opacities equation of state microscopic diffusion macroscopic: Convection rotation internal waves magnetic field et related transport INPUT PARAMETERS mass initial composition evolutionary state BOUNDARIES model atmospheres solar model Mode physics NUMERICS 10 The Sun 1- Opacities: mixture and choice of tables Z/X decrease : major impact in solar models radiative opacities Major differences just below the convection zone (Oxygen, Neon) 11 The Sun 1- Opacities: mixture and choice of tables Z/X decrease : major impact in solar models radiative opacities Major differences just below the convection zone (Oxygen, Neon) Check opacities: uncertainties assessed with OPAL/OP Opacity comparison for a 1 Msun calibrated solar model Difference in opacity dominated by the difference in the mixture (but less if AGS09 replaces AGS05). OP opacities give a better fit than OPAL. However in that region, there is no way to change the OP opacity by a sufficient amount to compensate the effects of mixture (Badnell et al. 2005) cf S. Basu ‘s talk S. Turck-Chieze ‘s talk 12 From the Sun to stars 1 Abundances Abundances of other stars determined by reference to the Sun, hence all stars affected can other stars be discriminating ? Impact of some mismatch between 3D atmosphere models (solar abundances) and 1D models (stellar abundances)? Z/X could be affected Impact of inconsistency when modelling other stars with AGS mixtures if their [Fe/H] not determined from 3D models? 13 The Sun 2-Nuclear reaction rates reaction cross section: in stars: reactions occur at low energy: few keV to 0.1 MeV rates from: • experimental data but to be extrapolated to low E • theory Yveline Lebreton GAIA-ELSA Conf., Sèvres, France, 10 June 2010 14 The Sun 2-Nuclear reaction rates recent significant progress in laboratory and theory ➥ S-factor down to the Gamow peak NOW and FUTURE low energy, high underground intensity reaction cross section: ➦ astrophysical factor (S-factor) 15 The Sun 2-Hydrogen burning reaction rates CNO cycle high mass or/and advanced stages CNO cycle pp chain 14N(p, γ)15O experimental measurements LUNA low mass stars S(0) ➘ 50% Adelberger et al. 2010 16 The Sun 2- 14N(p,γ)15O burning reaction rate CNO cycle efficiency is reduced Sun: ECNO/ETOT= 0.8% vs.1.6% before From the Sun to analogue stars convective core: smaller at given mass , appears at higher mass convective core smaller at given mass appears at higher mass NACRE, Angulo et al. 01 LUNA, Formicola et al. 04 1.2 M☉, Z=0.01 17 The Sun 2-Nuclear reaction rates reaction cross section S (E) (E) exp( 2) E Seismic sun (Basu et al 1997)- model Electron screening Salpeter 1954 Shaviv, Shaviv1996; 2000 Controversy Bahcall et al 2000 Weiss et al 2001 Dappen 2009 AGS09 AGS05 Model S switching off e- screening Model S Exact impact of e- screening ? 18 For the Sun and stars ? Christensen-Dalsgaard, 2009 The Sun 2-Hydrogen burning reaction rates CNO cycle high mass or/and advanced stages CNO cycle theoretical estimate only but helioseismic validation ➦ rate constrained to ±15% pp chain low mass stars Adelberger et al. 2010 p(p, e+ ν)d Weiss 2008 pp+screening increase by 15% : AGS05 cs prior to 2003 standard solar models below th UCZ 19 The Sun 3- Rotationally induced transport Open issues: flat rotation profile in the radiative region discrepancy for the sound speed below the UCZ Most recent, based on a model of diffusion-advection transport (Zahn 1992, Maeder, Zahn 1998, Chaboyer, Zahn, 1992, Mathis, Zahn 2004) Talon, Zahn 1997, high mass Mathias, Zahn, 1997 solar rotation profile Talon, Charbonnel 2003 Li dip 20 The Sun 3- Rotationally induced transport Open issues: flat rotation profile in the radiative region discrepancy for the sound speed below the UCZ Most recent, based on a model of diffusion-advection transport (Zahn 1992, Maeder, Zahn 1998, Chaboyer, Zahn, 1992, Mathis, Zahn 2004) Talon, Zahn 1997, high mass Mathias, Zahn, 1997 solar rotation profile Talon, Charbonnel 2003 Li dip Palacios et al 2006; Turck-Chieze et al 2010 : •Initial velocity (slow or ‘fast’ sun) matters •slow: microscopic diffusion dominates •Initially rapid enough: meridional circulation dominates over turbulent shear c 2 c2 GN93 mixture discrepancy for the sound speed below the UCZ increases 21 The Sun 3- Rotationally induced transport AGS05 • no rotation • rotation no surface J loss •rotation surface J loss Validity of prescriptions, in particular Dh ? Models from Marques 2010 Lebreton 2010 From the Sun to stars: Talon, Zahn 1997, Eggenberger et al, Decressin et al 2009, Marques et al 2010 22 22 The Sun 4-Internal wave induced transport For profile, needs additional transport processes: waves mixing or B Talon, Charbonnel 2005 internal waves ⊙ flat profil Li dip on the cool side B is also able to ⊙ flat profil Eggenberger et al 2005, Yang, Bi 2007 Open issue: either one ? or both ? depends on various precriptions and assumptions Sound speed Evolution of sound speed profil with age Talon 2010 with 2005 models (Talon, Charbonnel 2005) but not calibrated models yet For cs, needs higher opacities or higher helium below UZC ie higher He gradient Any mixing below UZC which smoothes the gradient goes in the wrong direction ? Then advection process? Waves ? 23 The Sun 5-Near surface layers Include - boundary: T- relation - Inefficient turbulent convection - Mode physics : nonadiabatic effects thermal and dynamics interaction radiation-pulsation interaction convection-pulsation Christensen-Dalsgaard , Perez Hernandez 1992 Christensen-Dalsgaard, Thompson 1997 24 The Sun 5-Model atmosphere and T- law Blue solar observations GOLF (credit F. Baudin) Red solar model GN93, diffusion (Lebreton 2010) From the Sun to stars, SSM uses semi empirical models or Kurucz models Evolutionary models for stars usually use Eddington T- 25 The Sun 5-Correcting for near surface effects Kjeldsen et al 2008 proposed a mean to correct for near surface effects Green : corrected with a(obs/0)b a,b fitted from the data reference frequency 0 = 3100 Hz fixed Green fall on blue points 26 The Sun 5-Correcting for near surface effects Of course valid only over the fitted domain,perhaps enough for stars How much parameters a,b, 0 do depend on the adopted model ? Validity for other stars ? 27 The Sun 5-Correcting for near surface effects Inefficient superadiabatic turbulent convection: 3D simulations Patched model versus non patched models: Frequencies closer to observed ones Rosenthal et al 1999, Li et al 2002 Samadi, Ludwig 2010 Existence of a similar scaling for that contribution to near surface effects ? Then it could be investigated theoretically 28 From the Sun to stars 5-Correcting for near surface effects Hotter stars, larger effects Pturb/Ptot larger, ‘lift’ of the atmosphere higher larger difference between patched and non patched model frequencies smaller gravity and/or higher température, larger Pturb/Ptot Models from Samadi, Ludwig 2010 curves : a(obs/max)b with adapted a,b Scaling not so easy … From the Sun to stars 5-Correcting for near surface effects … but possible Care with the ‘patching’ 3D simu not perfect 30 Stars From the Sun to solar-like oscillating MS stars: Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars) Stars can differ from the Sun by : Mass, age , Metallicity, Y Convective core Rotation …. Add additional issues: 31 Stars From the Sun to solar-like oscillating MS stars: Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars) Stars can differ from the Sun by : Mass, age , Metallicity, Y Convective core Rotation …. Add additional issues: •Determining input parameters: mass, age, chemical composition Y0, (Z/X)0, , ov, usually through location in HR diagram and spectroscopic information as accurate as possible L, Teff, Z/X, R… but M, R, age , surface chemical composition not well known; 32 Stars From the Sun to solar-like oscillating MS stars: Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars) Stars can differ from the Sun by : Mass, age , Metallicity, Y Convective core Rotation …. Add additional issues: • input parameters are needed: mass, age, chemical composition Y0, (Z/X)0, , ov, Most often M, R, age , surface chemical composition not well known; usually through location in HR diagram and spectroscopic information These incertainties family of models rather than a unique one and input physics dependent desentangling degeneracy of these effects on seismic diagnostics 33 Stars From the Sun to solar-like oscillating MS stars: Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars) Stars can differ from the Sun by : Mass, age , Metallicity, Y Convective core Rotation …. Add additional issues: • input parameters are needed: mass, age, chemical composition Y0, (Z/X)0, , ov, Most often M, R, age , surface chemical composition not well known; usually through location in HR diagram and spectroscopic information These incertainties family of models rather than a unique one and input physics dependent desentangling degeneracy of these effects on seismic diagnostics •For a given star, seismic observations can lead to 2 scenarii for mode degree identifications 34 Stars Observational constraints: •Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation: Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 35 Stars Observational constraints: •Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation: Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 Sensitivity to convective core properties: period related to acoustic radius of core convective radius:Provost et al, 1993 Mazumdar, Antia 2001; Miglio et al 2005, Roxburgh, Vorontsov 2007… d01 Deheuvels et al 2010 36 Stars Observational constraints: •Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation: Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 Sensitivity to convective core properties: period related to acoustic radius of core convective radius:Provost et al, 1993 Mazumdar, Antia 2001; Miglio et al 2005, Roxburgh, Vorontsov 2001, 2005, Roxburgh 2005 Base of the UCZ, Ionization regions d01 Monteiro et al 2000; Mazumdar, Antia 2001; Mazumdar et al 2006; Roxburgh, Vorontsov 2003 .. Deheuvels et al 2010 37 Stars Observational constraints: •Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation: Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 Sensitivity to convective core properties: period related to acoustic radius of core convective radius:Provost et al, 1993 Mazumdar, Antia 2001; Miglio et al 2005, Roxburgh, Vorontsov 2007… Base of the UCZ, Ionization regions d01 Monteiro et al 2000; Mazumdar, Antia 2001; Mazumdar et al 2006; Roxburgh, Vorontsov 2003 .. Age, core properties, low degree modes Houdek, Gough 2007, 2008 ; Cunha, Metcalfe 2007; Cunha 2010 Deheuvels et al 2010 38 Stars Observational constraints: •Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation: Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 Sensitivity to convective core properties: period related to acoustic radius of core convective radius:Provost et al, 1993 Mazumdar, Antia 2001; Miglio et al 2005, Roxburgh, Vorontsov 2007… d01 Base of the UCZ, Ionization regions Monteiro et al 2000; Mazumdar, Antia 2001; Mazumdar et al 2006; Roxburgh, Vorontsov 2003 .. Age, core properties, low degree modes Houdek, Gough 2007, 2008 ; Cunha, Metcalfe 2007; Cunha 2010 •Enough observed stars enable to relations Deheuvels et al 2010 validate systematic properties: scalings Bedding, Kjeldsen 2010, Kjeldsen et al 2008 39 Stars Initial abundances: the chemical mixture Evolved: isothermal core unevolved and ‘massive’: convective core , radiative interior, thin convective outer layer , rotation Different metallicity 40 Barban et al 2009 ; Baudin 2010, Ballot et al 2010; Benomar et al 2009 Stars 14N(p,γ)15O burning reaction rate CNO cycle efficiency is reduced convective core smaller at given mass appears at higher mass NACRE, Angulo et al. 01 LUNA, Formicola et al. 04 1.2 M☉, Z=0.01 41 Stars Gravitational settling and atomic diffusion: Ys decreases Effect increases with mass Diffusion too large for small envelope convective region ? Fe/H~0.08 M ~1.42-1.50 ov=0.-0.2 Fe/H~0.09 M ~1.30 Fe/H~0 M ~1.36-1.37 ov=0-0.2 Fe/H~-0.11 Fe/H~-0.44 M=1.1-1.15 ov ~0-0.2 1.1-1.2 Msol metal poor Compact with thin convective envelope Sun Fe/H~ -0.07 6 42 42 Stars Mode degree identification • (CoRoT) HD49933 Initial run 30 days 2 scenarii : A : need for large core overshoot B : need for intermediate core overshoot Appourchaux et al 2008 Initial run + long run 137 days + several independent data analyses scenario B is favored Benomar et al 2009 •(CoRoT) HD181420 2 scenarii : A : need for large core overshoot B : need for intermediate core overshoot Barban et al 2009 and others 43 Mode identification:scaling relations Bedding, Kjeldsen 2010 proposed to use scaling relations to help identifie the modes: scaled echelle diagram scales as < > ; scales as < > Test on ‘twin stars’: Sun and 18 Sco - Ceti and Cen B Reference star (CoRoT) HD49933 scenario B LR+IR ( Benomar et al 2009 •(CoRoT) HD181420 scenario 1 •(CoRoT) HD181906 scenario B Barban et al 2009, Gaulme et al 2009, Mosser 2010 Garcia et al 2009 44 Stars HD203608 Scenario A Mosser et al, 2008; Deheuvels et al 2010 Low mass F8V ~6070K; ~0.95 Msol, Fe/H ~-0.5 Scenario A: clear evidence that definetly requires mild overshoot and survical of convective core despite its small mass, old age but due low metallicity Ground based observations: 2 scenarii: arguments to choose scenario A but some check welcome 45 Stars HD203608 Scenario A Mosser et al, 2008; Deheuvels et al 2010 Low mass F8V ~6070K; ~0.95 Msol, Fe/H ~-0.5 Scenario A: clear evidence that definetly requires mild overshoot and survical of convective core despite its small mass, old age but due low metallicity Ground based observations: 2 scenarii: arguments to choose scenario A but some check welcome Scenario B clearly confirms scenario A Scenario B (Deheuvels, 2010, PhD) 46 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? 47 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? l=2 large error bars unreliable Calibration: large separation and small spacing d01 large separation • Mean value <> : given M, Z/X, Y, physics / : fix the age •Period of oscillation: acoustic depth of He++ ionisation • phase of oscillation: sensitive to _cgm to Y quite constraining together with non seismic constraints small spacing d01 sensitive to core conditions period = acoustic radius of convective core boundary 48 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? l=2 large error bars unreliable Calibration: large separation and small spacing d01 large separation • Mean value <> : given M, Z/X, Y, physics / : fix the age •Period of oscillation: acoustic depth of He++ ionisation • phase of oscillation: sensitive to _cgm to Y quite constraining together with non seismic constraints small spacing d01 sensitive to core conditions period = acoustic radius of convective core boundary AGS05: difficult to find a model satisfying all the constrains when Z/X is on the smaller part of the authorized interval 49 Stars HD49933 •Diffusion and helium surface abundance Effects of its low metallicity: AGS05 no diffusion AGS05 diffusion needs to start with large Yini needs to include Dturb still small Ys value, (Z/X) Ys=0.10 Less extreme AGS09: Ys=0.18 Scaling: /< > versus /< > oscillation phase independent of age 50 Stars HD49933: convective core •Diffusion Effects of its low metallicity: GN93: convective core, sensitivity to core overshoot; need for intermediate to large core overshoot _ov = 0.25-0.3Hp AGS05: small convective core , weak sensitivity to core overshoot but _ov cannot be zero Diffusion : mild overshoot _ov=0.21Hp 51 Stars HD49933: convective core •Diffusion and rotationally induced transport Initial angular rotation set to fit P=3.4 days at the age of HD49933 AGS05 no diffusion ov=0.2 Hp: does not fit Diffusion, ov=0.2 : fits Diffusion+rotation ov=0.2 : fits Diffusion+rotation no ov : does not fit But requires proper calibration Models computed by J. Marques 52 Echelle diagrams for HD49933 86 HZ for both Blue observations Red model 86.5 HZ for model 53 Stars HD181420 ( 6580K ; [Fe/H] ~0 or -0.12) Scenario 1 favors for intermediate core overshoot two models: 1.36 M with 0.2 Hp overshoot 1.37 M without overshoot No diffusion- No rotation Secondary oscillation component in the large separation not reproduced by models. Its ‘period’ corresponds to the base of the convective zone but is it real ? Provost 2010, Goupil et al 2009, Michel, Mazumdar 2010, Mosser 2010 Data from Barban et al; Gaulme et al, Benomar 54 et al Stars HD181420 rotation a ‘rapid’ rotator compared to the Sun With R=1.66 R and split = (3.±1 ) Hz Rotational velocity v = 21.9 ± 7.3 km/s =2/(GM/R3) = 320 l=2 ⊙ l=0 ! l=1 10km/s 27 55 Stars HD181420 rotation a ‘rapid’ rotator compared to the Sun With R=1.66 R and split = (3.±1 ) Hz Rotational velocity v = 21.9 ± 7.3 km/s =2/(GM/R3) = 320 l=2 ⊙ Effect of the non-spherically part of centrifugal distortion on échelle diagram and asymetries of splitting multiplets (WarM oscillation code) ! l=0 l=1 10km/s 25 km/s Asymetries of the splitting clearly appear in échelle diagram already at 10 km/s Contribute to surface effects 27 56 1.36 model with overshoot: Rotation (vrot=2, 15, 20, 25, 30 km/s) included in computing the eigenfrequencies* decreases the mean value of d01. Effect of rotation is included only through effect of nonspherical centrifugal distorsion on the frequencies The higher v, the lower d01 d01 indicates no oveshoot if vrot=20-25km/s or 0.2 Hp overshoot and vrot = 2 - 15 km/s rot = (4.5 ± 0.5) Hz spot = (5.144 ± 0.068) Hz split = (2.6 ± 0.4) Hz (scenario 1) (v sin i + R) (Fourier) (sismo) indication of rapid rotation ; differential in latitude Ratio vspot/nurot gives a constraint on spot model 25 57 Stars HD49385: mixed mode and mixture • Coupling between the pmode cavity and the gmode cavity weak coupling strong coupling => low-degree avoided crossings are associated with a characteristic distortion of the ridge in the échelle diagram (Deheuvels & Michel 2009) • Case of HD 49385 : detection of an l=1 avoided crossing based on the distortion of the ridge. 58 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting 59 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting GN93 overshooting 60 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting GN93 overshooting ASP05 no overshooting 61 Stars Kepler data and scaling relations Corot targets, ground based observations 4 Kepler targets provided by O. Creevey with permission of KASK group Some degeneracy in determining mass and age or radius due to the chemical composition Which accuracy in non seismic determination of Y,Z is needed ? 62 Conclusion Et tout le reste….. For exemple Semi convection versus mixing for low mass stars Stellar activity B 63 64 65 66 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? 67 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? l=2 large error bars unreliable Calibration: large separation and small spacing d01 large separation • Mean value <> : given M, Z/X, Y, physics / : fix the age •Period of oscillation: acoustic depth of He++ ionisation • phase of oscillation: sensitive to _cgm to Y quite constraining together with non seismic constraints small spacing d01 sensitive to core conditions period = acoustic radius of convective core boundary 68 Stars HD49933: a low metallicity low mass star Initial run + long run 137 days - Scenario B [Fe/H]=-0.4 +/- 0.1 How well current models can reproduce the observations? Can we find families of models satisfying all the obs. constraints? l=2 large error bars unreliable Calibration: large separation and small spacing d01 large separation • Mean value <> : given M, Z/X, Y, physics / : fix the age •Period of oscillation: acoustic depth of He++ ionisation • phase of oscillation: sensitive to _cgm to Y quite constraining together with non seismic constraints small spacing d01 sensitive to core conditions period = acoustic radius of convective core boundary AGS05: Difficult to find a model satisfying all the constrains when Z/X is on the smaller part of the authorized interval 69 Stars HD49933 •Diffusion and helium surface abundance Effects of its low metallicity: AGS05 no diffusion AGS05 diffusion needs to start with large Yini needs to include Dturb still small Ys value, (Z/X) Ys=0.10 Less extreme AGS09: Ys=0.18 70 Stars HD49933: convective core •Diffusion Effects of its low metallicity: GN93: convective core, sensitivity to core overshoot; need for intermediate to large core overshoot _ov = 0.25-0.3Hp AGS05: small convective core , weak sensitivity to core overshoot but _ov cannot be zero Diffusion : mild overshoot _ov=0.21Hp 71 Stars HD49933: convective core •Diffusion and rotationally induced transport Initial angular rotation set to fit P=3.4 days at the age of HD49933 AGS05 no diffusion ov=0.2 Hp: does not fit Diffusion, ov=0.2 : fits Diffusion+rotation ov=0.2 : fits Diffusion+rotation no ov : does not fit But requires proper calibration Models computed by J. Marques 72 Stars HD181420 ( 6580K ; [Fe/H] ~0 or -0.12) Scenario 1 favors for intermediate core overshoot two models: 1.36 M with 0.2 Hp overshoot 1.37 M without overshoot No diffusion- No rotation Secondary oscillation component in the large separation not reproduced by models. Its ‘period’ corresponds to the base of the convective zone but is it real ? Provost 2010, Goupil et al 2009, Michel, Mazumdar 2010, Mosser 2010 Data from Barban et al; Gaulme et al, Benomar 73 et al Stars HD181420 rotation a ‘rapid’ rotator compared to the Sun With R=1.66 R and split = (3.±1 ) Hz Rotational velocity v = 21.9 ± 7.3 km/s =2/(GM/R3) = 320 l=2 ⊙ Effect of the non-spherically part of centrifugal distortion on échelle diagram and asymetries of splitting multiplets (WarM oscillation code) ! l=0 l=1 10km/s 25 km/s Asymetries of the splitting clearly appear in échelle diagram already at 10 km/s Contribute to surface effects 27 74 1.36 model with overshoot: Rotation (vrot=2, 15, 20, 25, 30 km/s) included in computing the eigenfrequencies* decreases the mean value of d01. Effect of rotation is included only through effect of nonspherical centrifugal distorsion on the frequencies The higher v, the lower d01 d01 indicates no oveshoot if vrot=20-25km/s or 0.2 Hp overshoot and vrot = 2 - 15 km/s rot = (4.5 ± 0.5) Hz spot = (5.144 ± 0.068) Hz split = (2.6 ± 0.4) Hz (scenario 1) (v sin i + R) (Fourier) (sismo) indication of rapid rotation ; differential in latitude Ratio vspot/nurot gives a constraint on spot model 25 75 Stars HD49385: mixed mode and mixture • Coupling between the pmode cavity and the gmode cavity weak coupling strong coupling => low-degree avoided crossings are associated with a characteristic distortion of the ridge in the échelle diagram (Deheuvels & Michel 2009) • Case of HD 49385 : detection of an l=1 avoided crossing based on the distortion of the ridge. 76 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting 77 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting GN93 overshooting 78 Stars Models fitting all surface parameters + + frequency of the avoided croissing We fit the distortion of the ridge EZ (Deheuvels et al. 2010 in prep.) GN93 no overshooting GN93 overshooting ASP05 no overshooting 79 Stars Kepler data and scaling relations Corot targets, ground based observations 4 Kepler targets provided by O. Creevey with permission of KASK group Some degeneracy in determining mass and age or radius due to the chemical composition Which accuracy in non seismic determination of Y,Z is needed ? 80 Conclusion Et tout le reste….. For exemple Semi convection versus mixing for low mass stars Stellar activity B l=2, l=3 modes Mode physics …. 81 82