1. 1 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

2. 2 Outline I The Sun 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 Reviews: Basu, Antia 2008, Christensen-Dalsgaard, 2009; Turck Chieze et al, 2010

3. 3 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 r bzc -surface helium abundance Y s -ionization regions through  1 -sound speed profile : seismic solar model c(r ) -rotation profile  (r,  )

4. 4 - 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 - Major challenges and open issues in the solar case The Sun

5. 5 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) GN93GS98AGS05AGS09Lod09Caff10 Z/X0.02450.02290.01650.01810.01910.0209 1- Initial abundances: the solar mixture The Sun

6. 66 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) Grevesse & Noels 93, Grevesse & Sauval 1998, Asplund et al. 05, Asplund & al 09, Lodders et al. 09, Caffau et al 10 GN93GS98AGS05AGS09Lod09Caff10 Z/X0.02450.02290.01650.01810.01910.0209 1- Initial abundances: the solar mixture The Sun 2009-2010 Internal consistency of abundance determination from different ionisation levels of a given element Consensus between independent determinations

7. 7 1 Initial abundances: the solar mixture The Sun

8. 8 1 Initial abundances: the solar mixture The Sun

9. 9 1 Initial abundances: the solar mixture The Sun

10. 10 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 NUMERICS solar model Mode physics The sun

11. 11 1- Opacities: mixture and choice of tables The Sun Z/X decrease : major impact in solar models  radiative opacities Major differences just below the convection zone (Oxygen, Neon)

12. 12 1- Opacities: mixture and choice of tables The Sun 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 M sun 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

13. 13 1 Abundances Bailey et al. 07, Moses et al. 09 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? From the Sun to stars

14. 14 Yveline Lebreton GAIA-ELSA Conf., Sèvres, France, 10 June 2010 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 reaction cross section: 2-Nuclear reaction rates The Sun

15. 15 recent significant progress in laboratory and theory ➥ S-factor down to the Gamow peak NOW and FUTURE low energy, high intensity underground ➦ 2-Nuclear reaction rates The Sun reaction cross section: astrophysical factor (S-factor)

16. 16 Adelberger et al. 2010 high mass or/and advanced stages low mass stars CNO cycle pp chain 2-Hydrogen burning reaction rates CNO cycle S(0) ➘ 50% LUNA experimental measurements 14 N(p, γ ) 15 O The Sun

17. 17 CNO cycle efficiency is reduced Sun: E CNO /E TOT = 0.8% vs.1.6% before 2- 14 N(p, γ ) 15 O burning reaction rate From the Sun to analogue stars convective core: smaller at given mass, appears at higher mass LUNA, Formicola et al. 04 NACRE, Angulo et al. 01 convective core smaller at given mass appears at higher mass 1.2 M ☉, Z=0.01 The Sun

18. 18 reaction cross section Electron screening Seismic sun (Basu et al 1997)- model AGS05 Model S switching off e - screening Christensen-Dalsgaard, 2009 Salpeter 1954 Shaviv, Shaviv1996; 2000 Controversy Bahcall et al 2000 Weiss et al 2001 Dappen 2009 Exact impact of e - screening ? For the Sun and stars ? 2-Nuclear reaction rates The Sun AGS09

19. 19 Adelberger et al. 2010 high mass or/and advanced stages low mass stars CNO cycle pp chain p(p, e + ν)d 2-Hydrogen burning reaction rates CNO cycle The Sun theoretical estimate only but helioseismic validation ➦ rate constrained to ±15% Weiss 2008 pp+screening increase by 15% : AGS05 cs  prior to 2003 standard solar models below th UCZ

20. 20 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 3- Rotationally induced transport The Sun

21. 21 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 3- Rotationally induced transport The Sun GN93 mixture discrepancy for the sound speed below the UCZ increases

22. 22 The Sun 3- Rotationally induced transport Models from Marques 2010 Lebreton 2010 AGS05 no rotation rotation no surface J loss rotation surface J loss 22 From the Sun to stars: Talon, Zahn 1997, Eggenberger et al, Decressin et al 2009, Marques et al 2010 Validity of prescriptions, in particular Dh ?

23. 23 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 The Sun 23 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 ?

24. 24 Include - boundary: T-  relation - Inefficient turbulent convection - Mode physics : nonadiabatic effects thermal and dynamics interaction radiation-pulsation interaction convection-pulsation 5-Near surface layers The Sun Christensen-Dalsgaard, Perez Hernandez 1992 Christensen-Dalsgaard, Thompson 1997

25. 25 5-Model atmosphere and T-  law Blue solar observations GOLF (credit F. Baudin) Red solar model GN93, diffusion ( Lebreton 2010 ) The Sun From the Sun to stars, SSM uses semi empirical models or Kurucz models Evolutionary models for stars usually use Eddington T- 

26. 26 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 5-Correcting for near surface effects The Sun

27. 27 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 ? 5-Correcting for near surface effects The Sun

28. 28 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 The Sun Existence of a similar scaling for that contribution to near surface effects ? Then it could be investigated theoretically

29. 5-Correcting for near surface effects From the Sun to stars Hotter stars, larger effects P turb /P tot larger, ‘lift’ of the atmosphere higher larger difference between patched and non patched model frequencies smaller gravity and/or higher température, larger P turb /P tot curves : a( obs / max ) b with adapted a,b Scaling not so easy … Models from Samadi, Ludwig 2010

30. 30 5-Correcting for near surface effects From the Sun to stars … but possible Care with the ‘patching’ 3D simu not perfect

31. 31 Stars From the Sun to solar-like oscillating MS stars : Stars can differ from the Sun by : Mass, age, Metallicity, Y Convective core Rotation ….  Add additional issues: Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars)

32. 32 Stars From the Sun to solar-like oscillating MS 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 Y 0, (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; Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars)

33. 33 Stars From the Sun to solar-like oscillating MS 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 Y 0, (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 Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars)

34. 34 Stars From the Sun to solar-like oscillating MS 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 Y 0, (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 Here focus on low and intermediate mass MS up to ~ 1.5 Msol (F,G,K stars)

35. 35 Stars Additional seismic diagnostics and efforts in obtaining seismic constraints independent of models Mean large separation : Mosser Appourchaux, 2009, Roxburgh 2009, Mathur et al 2010 Observational constraints :

36. 36 Stars 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 Observational constraints : Deheuvels et al 2010

37. 37 Stars 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 Monteiro et al 2000; Mazumdar, Antia 2001; Mazumdar et al 2006 ; Roxburgh, Vorontsov 2003.. d01 Observational constraints : Deheuvels et al 2010

38. 38 Stars 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 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 d01 Observational constraints : Deheuvels et al 2010

39. 39 Stars 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 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 validate systematic properties: scalings relations Bedding, Kjeldsen 2010, Kjeldsen et al 2008 d01 Observational constraints : Deheuvels et al 2010

40. 40 Initial abundances: the chemical mixture Stars Barban et al 2009 ; Baudin 2010, Ballot et al 2010; Benomar et al 2009 unevolved and ‘massive’: convective core, radiative interior, thin convective outer layer, rotation Different metallicity Evolved: isothermal core

41. 41 LUNA, Formicola et al. 04 NACRE, Angulo et al. 01 CNO cycle efficiency is reduced 14 N(p, γ ) 15 O burning reaction rate convective core smaller at given mass appears at higher mass 1.2 M ☉, Z=0.01 Stars

42. 42 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 M ~1.36-1.37 ov=0-0.2 Fe/H~-0.44 M=1.1-1.15 ov ~0-0.2 Fe/H~ -0.07 42 Sun Fe/H~0.09 M ~1.30 Fe/H~-0.11 6 1.1-1.2 Msol metal poor Compact with thin convective envelope

43. 43 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 Stars

44. 44 Mode identification:scaling relations Bedding, Kjeldsen 2010 proposed to use scaling relations to help identifie the modes: scaled echelle diagram Reference star (CoRoT) HD49933 scenario B LR+IR ( Benomar et al 2009 (CoRoT) HD181420 scenario 1 Barban et al 2009, Gaulme et al 2009, Mosser 2010 (CoRoT) HD181906 scenario B Garcia et al 2009 scales as ;  scales as Test on ‘twin stars’: Sun and 18 Sco -  Ceti and  Cen B

45. 45 HD203608 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 A Stars

46. 46 HD203608 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 A Scenario B clearly confirms scenario A (Deheuvels, 2010, PhD) Stars

47. 47 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? Stars

48. 48 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? Stars 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

49. 49 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? Stars l=2 large error bars unreliable AGS05: difficult to find a model satisfying all the constrains when Z/X is on the smaller part of the authorized interval 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

50. 50 HD49933 Stars 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 Diffusion and helium surface abundance  / versus / Scaling: oscillation phase independent of age

51. 51 HD49933: convective core Stars 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 Diffusion

52. 52 HD49933: convective core Stars 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 Diffusion and rotationally induced transport Initial angular rotation set to fit P=3.4 days at the age of HD49933 Models computed by J. Marques

53. 53 Echelle diagrams for HD49933 Blue observations Red model 86  HZ for both 86.5  HZ for model

54. 54 HD181420 Scenario 1 favors for intermediate core overshoot Stars ( 6580K ; [Fe/H] ~0 or -0.12)‏ 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 et al

55. 55 l=0l=1 l=2 10km/s 27 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/R 3 ) = 320  ⊙ ! HD181420 Stars

56. 56 Effect of the non-spherically part of centrifugal distortion on échelle diagram and asymetries of splitting multiplets (WarM oscillation code) l=0l=1 l=2 10km/s 25 km/s Asymetries of the splitting clearly appear in échelle diagram already at 10 km/s Contribute to surface effects 27 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/R 3 ) = 320  ⊙ ! HD181420 Stars

57. 57 rot = ( 4.5 ± 0.5)  Hz (v sin i + R) spot = (5.144 ± 0.068)  Hz (Fourier) split = (2.6 ± 0.4)  Hz (scenario 1) (sismo) indication of rapid rotation ; differential in latitude Ratio v spot /nu rot gives a constraint on spot model Effect of rotation is included only through effect of nonspherical centrifugal distorsion on the frequencies 1.36 model with overshoot: Rotation (v rot =2, 15, 20, 25, 30 km/s)‏ included in computing the eigenfrequencies* decreases the mean value of d01. The higher v, the lower d01 d01 indicates no oveshoot if vrot=20-25km/s or 0.2 Hp overshoot and v rot = 2 - 15 km/s 25

58. 58 Coupling between the p- mode cavity and the g- mode cavity => low-degree avoided crossings are associated with a characteristic distortion of the ridge in the échelle diagram ( Deheuvels & Michel 2009 ) weak couplingstrong coupling Case of HD 49385 : detection of an l=1 avoided crossing based on the distortion of the ridge. HD49385: mixed mode and mixture Stars

59. 59 EZ GN93 no overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

60. 60 EZ GN93 no overshooting GN93 overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

61. 61 EZ GN93 no overshooting GN93 overshooting ASP05 no overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

62. 62 Kepler data and scaling relations 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 ? Corot targets, ground based observations 4 Kepler targets provided by O. Creevey with permission of KASK group Stars

63. 63 Conclusion Et tout le reste….. For exemple Semi convection versus mixing for low mass stars Stellar activity B

64. 64

65. 65

66. 66

67. 67 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? Stars

68. 68 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? Stars 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

69. 69 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? Stars l=2 large error bars unreliable AGS05: Difficult to find a model satisfying all the constrains when Z/X is on the smaller part of the authorized interval 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

70. 70 HD49933 Stars 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 Diffusion and helium surface abundance

71. 71 HD49933: convective core Stars 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 Diffusion

72. 72 HD49933: convective core Stars 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 Diffusion and rotationally induced transport Initial angular rotation set to fit P=3.4 days at the age of HD49933 Models computed by J. Marques

73. 73 HD181420 Scenario 1 favors for intermediate core overshoot Stars ( 6580K ; [Fe/H] ~0 or -0.12)‏ 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 et al

74. 74 Effect of the non-spherically part of centrifugal distortion on échelle diagram and asymetries of splitting multiplets (WarM oscillation code) l=0l=1 l=2 10km/s 25 km/s Asymetries of the splitting clearly appear in échelle diagram already at 10 km/s Contribute to surface effects 27 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/R 3 ) = 320  ⊙ ! HD181420 Stars

75. 75 rot = ( 4.5 ± 0.5)  Hz (v sin i + R) spot = (5.144 ± 0.068)  Hz (Fourier) split = (2.6 ± 0.4)  Hz (scenario 1) (sismo) indication of rapid rotation ; differential in latitude Ratio v spot /nu rot gives a constraint on spot model Effect of rotation is included only through effect of nonspherical centrifugal distorsion on the frequencies 1.36 model with overshoot: Rotation (v rot =2, 15, 20, 25, 30 km/s)‏ included in computing the eigenfrequencies* decreases the mean value of d01. The higher v, the lower d01 d01 indicates no oveshoot if vrot=20-25km/s or 0.2 Hp overshoot and v rot = 2 - 15 km/s 25

76. 76 Coupling between the p- mode cavity and the g- mode cavity => low-degree avoided crossings are associated with a characteristic distortion of the ridge in the échelle diagram ( Deheuvels & Michel 2009 ) weak couplingstrong coupling Case of HD 49385 : detection of an l=1 avoided crossing based on the distortion of the ridge. HD49385: mixed mode and mixture Stars

77. 77 EZ GN93 no overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

78. 78 EZ GN93 no overshooting GN93 overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

79. 79 EZ GN93 no overshooting GN93 overshooting ASP05 no overshooting Models fitting all surface parameters +  + frequency of the avoided croissing We fit the distortion of the ridge (Deheuvels et al. 2010 in prep.) Stars

80. 80 Kepler data and scaling relations 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 ? Corot targets, ground based observations 4 Kepler targets provided by O. Creevey with permission of KASK group Stars

81. 81 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 ….

82. 82