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Prospects for asteroseismology of solar-like stars

Prospects for asteroseismology of solar-like stars. T. Appourchaux Institut d’Astrophysique Spatiale , Orsay. Contents. What is a solar-like star? A shopping list for physics The store: PLATO 2.0 Summary. What is meant by a solar-like star?. Huber ( 2014). Huber et al (2011).

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Prospects for asteroseismology of solar-like stars

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  1. Prospects for asteroseismology of solar-like stars T. Appourchaux Institut d’Astrophysique Spatiale, Orsay

  2. Contents Whatis a solar-like star? A shopping list for physics The store: PLATO 2.0 Summary

  3. What is meant by a solar-like star? Huber (2014) Huber et al (2011) Houdek et al (2000)

  4. Shopping list for physics Internal rotation (Subgiant stars, MS star) Heliumionization and convection zones Excitation and damping (mode physics) Stellar cycle and activity Atmosphere: surface effect, asymmetries Stellar Radius, Mass and Age Clusters and Binary stars

  5. Rotation in solar-like stars Nielsen et al (2014) Seismically derived rotation provides light on differential rotation and gyrochronology (a few stars) Davies et al (2014)

  6. Rotation in evolved stars Deheuvels et al (2014) g-mode like p-mode like Subgiant stars having mixed modes provides the stellar rotation as a function of depth (6 stars)

  7. Second differences: in depths... Mazumdar et al (2014) BCZ HeII Signatures and depths of the base of the convection and second Helium ionization zones (20 stars)

  8. ...leading to Helium abundance Verma et al (2014) Amplitude of the signature of the second Helium ionization zone as a marker of helium abundance (1 star)

  9. Mode physics: linewidth et al Appourchaux et al (2014) Different inferred background affects mode-physic parameters (and vice versa)

  10. Stellar linewidths Appourchaux et al (2014) Linewidth depressionatnmaxdecreaseswith effective temperature (23 stars)

  11. Stellar activity Garcia et al (2013) Garcia et al (2010) Sun HD49933 Studies of stellar activity impact on seismic parameters to be done on more stars than just 2!

  12. Departure from Lorentzian mode profile (asymmetry) Toutain and Kosovichev (2005) Mode asymmetry yet to be detected in other stars than the Sun (impact on stellar modelling)

  13. Surface effects Ball and Gizon (2014) Understanding and proper modelling of surface effect key for stellar modelling (8 stars)

  14. Stellar mass and radius Huber et al (2012) • Calibration of scaling laws using interferometry • From scaling laws to stellar modelling Lebreton and Goupil (2014) White et al (2014)

  15. Stellar age No seismic proxy for stellar age (yet), model comparison required using frequencies and /or ratio Lebreton and Goupil (2014) Metcalfe et al (2012) Age determination on single stars (>50 stars) Age calibration possible on binary stars (3 binary stars)

  16. Binary stars A "typical" seismic binary (Kepler) "Speckle-Interferometry" binary Chaplin et al (2014) Appourchaux et al (2012) Seismic binary detection 0.5% for MS and subgiant stars to 1% for Red giants

  17. Clusters Appourchaux et al (1993) Stello et al (2011) Improved stellar age precision and other stellar parameters with cluster by a factor 3 (No cluster MS stars but...cluster RG stars) Seismic scaling relation provides ways of identifying cluster members

  18. PLATO 2.0 Credits: G. Perez Diaz, IAC (MultiMedia Service)

  19. PLATO 2.0 in short • - Selected by ESA in February 2014 • - 32 « Normal » 12cm cameras, cadence 25 s, white light • 2 «Fast » 12cm cameras, cadence 2.5 s, 2 colours • Dynamicrange: 4 ≤ mV ≤ 16 • L2 orbit • Nominal mission duration: 6 years launched in 2024 • 2 longpointings of 2-3 years + step-and-starephase (2-5 months per pointing)

  20. PLATO 2.0 targets For the Baseline mission

  21. Summary • Stellar physics will face a revolution with PLATO 2.0 • Stellar physics will improve in the following fields: • Stellar evolution • Internal structure and rotation (g modes?) • Convection zone, HeII zone • Stellar activity • Seismic inversion and diagnostics (left out here...) • Stellar physics will be calibrated with: • Binary stars and clusters

  22. PLATO 2.0 observing strategy • Baseline observingstrategy: • 6 years nominal scienceoperation • 2 longpointingsof 2-3 years + step-and-starephase (2-5 months per pointing)

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