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C HALLENGES FOR STELLAR EVOLUTION AND PULSATION THEORY

C HALLENGES FOR STELLAR EVOLUTION AND PULSATION THEORY. J adwiga D aszy ń ska- D aszkiewicz Instytut Astronomic zny, Uniwersytet Wrocław ski , P OLAND. JENAM Symposium "Asteroseismology and stellar evolution" September 8, 2 00 8, Vienna.

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C HALLENGES FOR STELLAR EVOLUTION AND PULSATION THEORY

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  1. CHALLENGES FOR STELLAR EVOLUTION AND PULSATION THEORY JadwigaDaszyńska-Daszkiewicz Instytut Astronomiczny, Uniwersytet Wrocławski, POLAND JENAM Symposium "Asteroseismology and stellar evolution" September 8, 2008, Vienna

  2. DIVERSITY OFSTELLAR PULSATION J. Christensen-Dalsgaard

  3. Amplitude frequency [c/d] mode identification: osc→(n,,m) ASTEROSEISMOLOGY

  4. SEISMIC MODEL j,obs=j,cal(nj , j , mj , PS ,PT) PS -- parameters of the model: the initial values of M0, X0, Z0, the angular momentum (or Vrot,0), age (or logTeff) PT -- free parameters of the theory: convection, overshooting distance, parameters describing mass loss, angular momentum evolution, magnetic field

  5. SOME OBSERVATIONAL KEY PROBLEMS

  6. CLASSICAL CEPHEIDS primary distanceindicators

  7. Mass discrepancy problem for double mode Cepheids pulsational masses  evolutionary masses

  8. Petersen Diagram (P1/P0 vs logP0 ) for  Scuti stars and double mode Cepheids LAOL & OPAL tables Moskalik i in, 1992 Christensen-Dalsgaard 1993

  9. Mass discrepancy remains ML relation dependence Keller 2008 Z dependence mass loss ? internal mixing ? Keller, Wood 2006

  10. double mode Cepheids models result from ignoring bouyancy in convectively stable layers ! Smolec R., Moskalik P., 2008 Growth rates: 0,1-for the fundamental mode with respect to the first overton, 1,0-for the first overton double mode solution is not found !

  11. another interesting facts (OGLE): nonradial modes in Classical Cepheids  Blazhko Cepheids  1O/3O double-mode Cepheids single mode 2O Cepheids triple-mode Cepheids  eclipsing binary systems containing Cepheids Udalski, Soszyński Kołaczkowski, Moskalik, Mizerski

  12. Period–luminosity diagrams for Classical Cepheids in the LMC OGLE Data Soszyński et al. 2008

  13. B type main sequence pulsators M>8M - progenitors of Type II Supernova (most  Cep’s) M<8M – form CNO elements (most SPB stars)

  14.  Cep and SBB stars in Magellanic Clouds Pigulski, Kołaczkowski (2002) Kołaczkowski, 2004, PhD Kołaczkowski et al. (2006) Karoff et al. (2008) LMC Z=0.008 SMC Z=0.004

  15. Pamyatnykh, Ziomek

  16. Miglio, Montalban, Dupret

  17. problem of mode excitation  uncertainties in opacityand element distribution  extent of overshootingdistance  estimate of the interior rotation rate

  18. Dziembowski, Pamyatnykh 2008

  19. sdB stars core helium burning phase thin hydrogen envelope final stage before white dwarfs

  20. sdB PULSATORS Charpinet et al. 1996 – theoretical predication Kilkenny et al. 1997 – observational evidence Green et al. 2003 – long period oscillations Fontaine et al. 2003 – iron accumulation in Z-bump Fontaine et al. 2006 – including radiative levitation

  21. Inner structure and origin ?  single star evolution  binary star evolution -- common envelope evolution -- stable Roche-lobe overflow -- the merge of two He WD stars

  22. sdO stars  C/O core helium burning shell phase

  23. Rodriguez-Lopez, Ulla, Garrido, 2007 sdO PULSATORS Woudt, Kilkenny, Zietsman et al. 2006 SDSS object: 13 independent frequencies (P=60-120 s) Rodriguez-Lopez, Ulla, Garrido, 2007 two pulsating candidates in their search (P=500s and 100 s)

  24. Iron levitation in the pure hydrogen medium Mode excited in the range P105-120 s

  25. inner structure and origin ? „luminous” sdO  post-AGB stars „compact” sdO  post-EHB objects, descendants of sdBs  He-sdOs – the merger of two He WDs or deleyed core He flash scenario

  26. sdOB pulsators – perfect object for testing diffusion processes hybrid sdOB pulsators - Schuh et al. 2006

  27. Extreme helium stars

  28. Detection of variability in hydrogen deficient Bp supergiants: V652 Her (P=0.108d), V2076 Oph (P=0.7-1.1d)– Landlot 1975 strange-mode instability – high L/M ratio Z-bump instability Jeffery 2008

  29. Origin and connection (if any) between normal and the He-rich stars

  30. helium-rich sdB star Pulsation in high order g-modes such modes should be stable Ahmad, Jeffery 2005

  31. Hot DQ White Dwarf stars Carbon atmospheres with little or no trace of H and He new sequence of post-AGB evolution

  32. Dufour, Liebert, Fontaine, Behara, 2007, Nature 450, 522 White dwarf stars with carbon atmospheres Six hot DQ White Dwarfs

  33. Montgomery et al. 2008, ApJ 678, L51 SDSS J142625.71575218.3: A Prototype for a new class variable white dwarfs P=417.7 [s] from time-series potometry Period [s] 417 208 83 new class of pulsating carbon-atmosphere WDs (DQVs) or first cataclysmic variable with a carbon-dominated spectrum

  34. Fontaine, Brassard, Dufour, 2008, A&A 483, L1 Might carbon-atmosphere white dwarfs harbour a new type of pulsating star? Unstable low-order g-modes for models with Teff from 18 400 K to 12 600 K, log g = 8.0, X(C) = X(He) = 0.5 Pulsation in hotter models can be excited if surface gravity is increased or if convective is more efficient Dufour, Fontaine et al. 2008, ApJ 683, L167 SDSS J142625.71575218.3: The first pulsating white dwarf witha large detectable magnetic field

  35. EVOLUTION OF PLANETARY SYSTEMS Planets around oscillating solar type stars e.g.  Ara Planets around compact pulsators V391 Peg, Silvotti et al. 2007

  36. SOME THEORETICAL KEY PROBLEMS

  37. OPACITIES determine the transport of radiation through matter (T,, Xi)

  38. LAOL (Los Alamos Opacity Library)till ~1990 Simon (1982) suggestion that the opacity were at fault OPAL(OPAcity Library) F.J. Rogers, C.A. Iglesias i in. 1990 ApJ 360, 221 1992 ApJ 397, 717; ApJS 79, 507 1994 Science 263, 50 1996 ApJ 456, 902 OP (Opacity Project) International team led by M.J. Seatona 1993 MNRAS 265, L25 1996 MNRAS 279, 95 2005 MNRAS 360, 458, MNRAS 362, L1

  39. Opacity in the  Cephei model (M=12 M, X=0.70, Z=0.02): OP (Seaton et al.) vs. OPAL (Livermore) vs. LAOL (Los Alamos) (< 1991) A. A. Pamyatnykh

  40.  (OPAL) as a function of logT and log/T63 (T6 =T/106) C/O bump Pamyatnykh 1999, AcA 49, 119

  41. CONESQUENCES OF Z-BUMP Seismic model of the Sun improved  Cepheids mass discrepancy solved pulsation of B type MS stars explained sdB and sdO pulsation pulsation of someextreme He stars OSCILLATION FREQUENCIES TEST OF STELLAR OPACITY

  42. NEW SOLAR CHEMICAL COMPOSITION Asplund, Grevesse, Sauval 2004, 2005

  43. Comparison of the old and new solar composition A. A. Pamyatnykh

  44. better agreement of solar metallicity with its neighbourhood No problem with B main sequence pulsators Pamyatnykh (2007): more Fe relative to CNO For AGS04 galactic beat Cepheid models are in better agreement with observations Buchler, Szabo 2007 Reductionof thelithium depletion in pre-main sequence stellar models gives better agreement withobservations, Montalban,D’Antona 2006

  45. Conspiracy at work: better is worse Basu & Antia, 2007, astro-ph0711.4590

  46. ROTATION

  47. Achernar: the ratio of the axes is 1.56 ± 0.05

  48. 1.Structure (spherical symetry broken) 2.mixing (meridional circulation, shear instabilities, diffusion, transport, horizontal turbulence) distribution of internal angular momentum (the rotation velocity at different depths) 3.mass loss from the surface enhanced by the rapid rotation (the centrifugal effect) Laplace, Jacobi, Lioville, Riemann, Poincare, Kelvin, Jeans, Eddington, von Zeipel, Lebovitz, Lyttleton, Schwarzachild, Chandrasekhar, Kippenhahn, Weigert, Sweet, Öpik, Tassoul, Roxgurgh, Zahn, Spruit, Deupree,Talon, Maynet, Maeder, Mathis and many others

  49. Evolutionary tracks for non–rotatingand rotating models Maynet, Maeder, 2000

  50. The evolution of (r) during the MS evolution of a 20Mstar Maynet, Maeder, 2000

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