Inflated Planets Orbiting Evolved Stars

Transcript

1. INFLATED PLANETS ORBITING EVOLVED STARS: TOWARD SOLVING A 17-YEAR OLD PROBLEM IN EXOPLANET SCIENCE SAM GRUNBLATT1, DAN HUBER1, ERIC GAIDOS1, ERIC LOPEZ2 1. UNIVERSITY OF HAWAII 2. NASA GODDARD SPACE FLIGHT CENTER Image credit: C. Carreau / ESA
2. Inflated Hot Jupiters are ubiquitous. Lopez & Fortney (2016)
3. Inflated Hot Jupiters are ubiquitous. Lopez & Fortney (2016) maximum expected radius
4. Lopez & Fortney (2016) maximum expected radius highly inflated not inflated Inflated Hot Jupiters are ubiquitous.
5. The Mechanism of Planet Inflation Batygin & Stevenson (2010) Class I: planet inflated directly by increased stellar irradiation Class II: delayed cooling after planet formation Chabrier & Baraffe (2007)
6. How to distinguish between Classes I and II? Class I: re-inflation Class II: no re-inflation
7. A SEARCH FOR GIANTS ORBITING GIANTS WITH K2 ➤ 10,000 initial targets ➤ K2 long cadence limit for asteroseismology: 283 μHz (~3.5 Rsun) ➤ Transit detection limit: ~10 Rsun ➤ Temperature: 4500— 5500 K (fewer horizontal branch stars) ➤ 2744 asteroseismic detections Huber et al. (2016)
8. FIRST K2 TRANSITING PLANET AROUND OSCILLATING STAR Grunblatt et al. (2016)
9. TWO TRANSITING PLANETS AROUND ASTEROSEISMIC HOSTS Grunblatt et al. (submitted)
10. TWO NEW TRANSITING PLANETS AROUND ASTEROSEISMIC HOSTS Grunblatt et al. (submitted)
11. Asteroseismology Radii: ≤3-5% Masses: ≤5-10% log(g): within 0.01 dex Grunblatt et al. (2016)
12. Asteroseismology Radii: ~3-5% Masses: ~5-10% log(g): within 0.01 dex Grunblatt et al. (2016)
13. Asteroseismology Radii: ~3-5% Masses: ~5-10% log(g): within 0.01 dex Grunblatt et al. (2016)
14. Asteroseismology Radii: ~3-5% Masses: ~5-10% log(g): within 0.01 dex Grunblatt et al. (2016)
15. Asteroseismology Grunblatt et al. (2016) Rs = 4.20 +/- 0.14 R⊙ Ms = 1.16 +/- 0.12 M⊙
16. Asteroseismology Grunblatt et al. (submitted) Rs = 3.85 +/- 0.13 R⊙ Ms = 1.08 +/- 0.08 M⊙
17. TWO NEW TRANSITING PLANETS AROUND ASTEROSEISMIC HOSTS Grunblatt et al. (submitted)
18. TWO NEW TRANSITING PLANETS AROUND ASTEROSEISMIC HOSTS Grunblatt et al. (submitted) Rp = 1.27 +/- 0.07 RJ Rp = 1.31 +/- 0.11 RJ
19. PLANET MASS MEASUREMENT: KECK/HIRES RADIAL VELOCITIES Mp = 0.48 +/- 0.07 MJ Mp = 0.49 +/- 0.06 MJ Grunblatt et al. (submitted)
20. Are they inflated planets?
21. Are they inflated planets?
22. Are they inflated planets? Yes.
23. Are they re-inflated planets? avg incident flux on main sequence: K2-97b: 
 170 +140 -60 F EPIC2287b: 190 +150 -80 F Grunblatt et al. (submitted)
24. Are they re-inflated planets? typical incident flux for ~1.3 RJ planets avg incident flux on main sequence: K2-97b: 
 170 +140 -60 F EPIC2287b: 190 +150 -80 F current incident fluxes Grunblatt et al. (submitted)
25. K2-97b, EPIC2287b in context Rp = 1.3 +/- 0.1 RJ Mp = 0.5 +/- 0.1 MJ current inc. fluxes: 800-1200 F MS incident fluxes: 100-400 F
26. Data implies 0.023%+0.023% -0.012% heating efficiency Class II ] Class I Results consistent with re-inflation. Grunblatt et al. (submitted)
27. Data implies 0.033%+0.037% -0.021% heating efficiency Class II ] Class I Results consistent with re-inflation. Grunblatt et al. (submitted)
28. Summary The first transiting planets found orbiting oscillating stars with K2: 
 ~1.3 RJ, ~0.5 MJ, ~9 day period 
 (Mp, Rp, M*, R*, Porb agree within 10%) Consistent with planet re-inflation during RGB phase
 Seeing Double with K2: Testing Re-Inflation With Two Remarkably Similar Planets Around Red Giant Stars Grunblatt et al. (submitted)
29. Appendix. Why are they so similar? 0.01 0.10 1.00 10.00 planet mass (Jupiters) 0.0 0.2 0.4 0.6 0.8 1.0 survey bias factor Short answer: probably survey bias * intrinsic planet occurrence
30. Appendix. Gaussian process lightcurve fitting Used squared exponential and simple harmonic oscillator GP kernel functions to account for granulation noise
31. Appendix. Gaussian process lightcurve fitting Derived planet radii that agree within 0.5σ for both GP models.
32. Appendix: Red Giant Planet Occurrence ? ? ? ? ? ? Expected yield: ~5 planets. New candidates incoming! EPIC228754001.01 K2-97b
33. Is post-MS evolution affecting planet occurrence? 2 confirmed planet in 2744 LLRGB stars searched. Expected yield: ~3 planets. Deficit potentially supported by RV surveys of subgiant stars (Sato et al. 2013) Theories expect decrease (Spiegel & Madhusudan 2012) But by how much? Currently still small # stats.