Exoplanet-Asteroseismology Synergies

1. Exoplanet-Asteroseismology Synergies Bill Chaplin, School of Physics & Astronomy University of Birmingham, UK EAHS2012, Oxford, 2012 March 15

2. Oscillations as clocks: FM stars Shibahashi & Kurtz (2012), MNRAS, submitted (arXiv:1202.0105)

3. Oscillations as clocks: V391 Peg Silvotti et al. (2007), Nature, 449, 189

4. O-C diagram, prominent oscillation frequencies of V391 Peg Frequency #1 Frequency #2 Silvotti et al. (2007), Nature, 449, 189

5. Understanding stellar systems like our own…

6. Evolution and properties of stellar systems • Precise, accurate fundamental stellar properties for modelling exoplanet systems: • Seismic densities, radii, masses, ages • Seismic log(g) for “boot strapping” spectroscopic analysis

7. Evolution and properties of stellar systems • Internal rotation, stellar angle of inclination: • Constraints on dynamical histories of stellar systems

8. Evolution and properties of stellar systems • Intrinsic activity, variability of host stars, influence on local environment: • “Sound” stellar activity cycles • Depths of convective envelopes, tests of stellar dynamos

9. asteroFLAG Hare and Hounds Stello, Chaplin et al. 2009, ApJ

10. asteroFLAG Hare and Hounds

11. Asteroseismic ensemble tests Kepler Input Catalogue Finds an underestimation bias in KIC radii KIC – seismic log g (dex) KIC – seismic radii (%) Verner et al., 2011, ApJ, 738, L28

12. Inferences on stellar activity, stellar cycles, activity of the “Sun in time”

13. Kepler: Gtype dwarf Sun (SOHO/VIRGO)

14. Sun (SOHO/VIRGO)

15. Frequency spectrum of Cyg Activity Granulation Solar-like oscillations Guzik et al. (2012), in preparation

16. Stellar activity suppresses oscillations Inference on magnetic fields and convection Proxy for “stellar activity” Detected oscillations? yes no Teff (K) Chaplin et al., 2011, ApJ, 732, 5L

17. “Sounding” stellar activity cycles: Sun Broomhall et al., 2009, ApJ, 700, L162

18. Quasi-biennial variation After removal of 11-yr cycle signature Broomhall et al., 2012, ApJ, 420, 1405

19. CoRoT reveals a short activity cycle in HD49933 García et al., 2010, Science, 329, 1032

20. One example from the seismic Zoo Variation of seismic frequencies and amplitudes Oscillation amplitudes Oscillation frequencies Light curve Courtesy Salabert (Elsworth et al., work in progress)

21. Inference: surface distribution of activitysizes and phases of frequency shifts depend on (l, m) • Inference on distribution: • From frequency shifts of different modes • From frequency asymmetry of components of non-radial modes Chaplin (2011), Proceedings Tenerife Winter School

22. Inference: surface distribution of activitysizes and phases of frequency shifts depend on (l, m) • Activity distribution: non homogeneous, preferred bands of latitude • Response of modes: depends on (l, m) Chaplin (2011), Proceedings Tenerife Winter School

23. Effects of near-surface activity on modesDepends on spherical harmonic of mode (l, m) (1,0) (1,1) (2,0) (2,1) (2,2) (3,0)

24. Inference on active latitudes Spatial dependence of the frequency shifts Predicted shifts simple model for latitudinal distribution surface activity Match to observed ratios Chaplin et al. 2007, MNRAS, 377, 17

25. Inference on active latitudes Spatial dependence of the frequency shifts Predicted shifts simple model for latitudinal distribution surface activity Match to observed ratios Chaplin et al. 2007, MNRAS, 377, 17

26. Inference on active latitudes Spatial dependence of the frequency shifts Predicted shifts simple model for latitudinal distribution surface activity Match to observed ratios Chaplin et al. 2007, MNRAS, 377, 17

27. Inference on active latitudes Spatial dependence of the frequency shifts Predicted shifts simple model for latitudinal distribution surface activity Match to observed ratios Chaplin et al. 2007, MNRAS, 377, 17

28. Inference: surface distribution of activity sizes and phases of frequency shifts depend on (l, m) Sun-as-a-star data max=40 ± 10 degrees Chaplin (2011), Proceedings Tenerife Winter School

29. Stellar activity squashes mode peaks!  = 0.0 0.15 1.5 0.4 3.0 See Chaplin et al., 2008, MNRAS, 384, 1668

30. Asteroseismic analysis Kepler Objects of Interest (KOIs) Credit: IAC

31. Seismology of exoplanet host stars HAT-P-7 Christensen-Dalsgaard et al. 2010 Kepler-10b Batalha et al. 2011

32. Kepler 21b1.6RE planet orbiting bright F-type sub-giant Howell et al. (2012), ApJ, 746, 123

33. Kepler 21b1.6RE planet orbiting bright F-type sub-giant • Brightest Kepler exoplanet host star • High-precision stellar properties from asteroseismology: • Stellar radius to 2.2% • Stellar mass to 4.5% • Stellar age to 12% • Planetary radius to 2.4%

35. Kepler 22b2.4RE planet in habitable zone of Sun-like star Strong signature of large frequency separation Borucki et al. (2012), ApJ, 745, 120

36. Inclination affects mode visibility (1,0) (1,1) (2,0) (2,1) (2,2) (3,0)

37. Inclination affects mode visibility +2 m=1 0 +1 m=2 1 0 +1 l =1 l =2 Gizon & Solanki, 2003, ApJ, 589, 1009

38. Inference on stellar inclination 2 yrs Height ratios depend on angle

39. Inference on stellar inclination 1 month Need long datasets

40. Fin