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

2. Contents What is a solar-like star? A shopping list for physics The store: PLATO 2.0 Summary 2HELAS VI: Helioseismology and applications

3. What is meant by a solar-like star? 3HELAS VI: Helioseismology and applications Houdek et al (2000) Huber (2014) Huber et al (2011)

4. Shopping list for physics Internal rotation (Subgiant stars, MS star) Helium ionization 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 4HELAS VI: Helioseismology and applications

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

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

7. Second differences: in depths... 7HELAS VI: Helioseismology and applications 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 8 HELAS VI: Helioseismology and applications 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 9HELAS VI: Helioseismology and applications Appourchaux et al (2014) Different inferred background affects mode-physic parameters (and vice versa)

10. Stellar linewidths 10HELAS VI: Helioseismology and applications Appourchaux et al (2014) Linewidth depression at max decreases with effective temperature (23 stars)

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

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

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

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

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

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

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

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

19. PLATO 2.0 in short 19HELAS VI: Helioseismology and applications - 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 - Dynamic range: 4 ≤ m V ≤ 16 - L2 orbit - Nominal mission duration: 6 years launched in 2024 - 2 long pointings of 2-3 years + step-and-stare phase (2-5 months per pointing)

20. PLATO 2.0 targets 20HELAS VI: Helioseismology and applications 4300 deg 2 (long stare fields) 20,000 deg 2 (plus step and stare fields) Noise Level (ppm/√hr) Number of cool stars mVmV 34 (Asteroseismology ) 22,0009.8-11.385,000 80 (Earth radius detection) 267,00011.6-12.91,000,000 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 21HELAS VI: Helioseismology and applications

22. PLATO 2.0 observing strategy 22HELAS VI: Helioseismology and applications Baseline observing strategy: 6 years nominal science operation 2 long pointings of 2-3 years + step-and-stare phase (2-5 months per pointing)