Planet Occurrence Within 0.25 AU

Transcription

1 Planet Occurrence Within 0.25 AU Andrew W. Howard UC Berkeley California Planet Search Team: Geoff Marcy, Debra Fischer, John Johnson, Jason Wright, Howard Isaacson, Julien Spronck, Jeff ValenO, Jay Anderson, Nikolai Piskunov, more! Photo credit: Laurie Hatch

2 Acknowledgements NASA: Kepler PI: Bill Borucki & Deputy PI: David Koch Ball Aerospace The Kepler Team:

3 Well-Characterized Planets

4 Well-Characterized Planets HZ

5 Well-Characterized Planets Close-in Planets HZ

6 Well-Characterized Planets Close-in Planets Measure planet mass & radius functions Constrain planet densities Probe planet formation and migration Test population synthesis models Guide future searches HZ

7 Well-Characterized Planets Close-in Planets Measure planet mass & radius functions Constrain planet densities Probe planet formation and migration Test population synthesis models Guide future searches HZ

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9 50 days 2 Earth Radii 95% True planets - Morton and Johnson (2011)

10 Choose Subset of Planets/Stars for High Detectability Only GK dwarfs (T eff /logg) Only bright stars (Kp < 15) Only high SNR transits (SNR > 10 in 90 days) KOI Full sample Restricted sample ~156,000 stars ~58,000 stars 1,230 planets 438 planets P= d Rp=2.4 Re

11 Choose Subset of Planets/Stars for High Detectability GK dwarfs Only GK dwarfs (T eff /logg) Only bright stars (Kp < 15) Only high SNR transits (SNR > 10 in 90 days) KOI Full sample Restricted sample ~156,000 stars ~58,000 stars 1,230 planets 438 planets P= d Rp=2.4 Re

12 Choose Subset of Planets/Stars for High Detectability GK dwarfs Only GK dwarfs (T eff /logg) Only bright stars (Kp < 15) Only high SNR transits (SNR > 10 in 90 days) SNR 10 KOI Full sample Restricted sample ~156,000 stars ~58,000 stars 1,230 planets 438 planets P= d Rp=2.4 Re

13 Howard et al. (2011c)

14 Howard et al. (2011c)

15 Compute Planet Occurrence in Small Domain Howard et al. (2011c)

16 Compute Planet Occurrence in Small Domain Correct for: Transit probabilities - ptransit = R /a Incompleteness - some stars lack the photometric sensitivity 2R Howard et al. (2011c)

17 Howard et al. (2011c)

18 Howard et al. (2011c)

19 Planet Radius Distribution Number of Planets per Star with P < 50 days Planet Radius (R E ) Power law: dn/dlogr = kr α k = 2.9 ± 0.5 α = ± 0.11 Howard et al. (2011c)

20 Number of Planets per Star with P < 50 days Planet Radius Distribution Kepler Howard et al. 2011c, ApJ submitted, arxiv: Planet Radius (R E ) Planet Mass Distribution Eta-Earth Survey (Doppler) Howard et al. 2010, Science, 330, 653 Power Law Radius Function df/dlogr = kr α k = 2.9±0.5, α = -1.92±0.5 Power Law Mass Function df/dlogm = km α k = , α = Extrapolate: η Earth = % Msini = M E, P < 50 days

21 Back to Kepler: Planet Period Distribution Howard et al. (2011c)

22 Power Law Increasing Planet Occurrence per log P bin Power law with Exponential Cutoff: dn/dlogp = kp β (1-exp((P/P0) γ )) Howard et al. (2011c)

23 Exponential Cutoff Power Law Increasing Planet Occurrence per log P bin Power law with Exponential Cutoff: dn/dlogp = kp β (1-exp((P/P0) γ )) Howard et al. (2011c)

24 Howard et al. (2011c)

25 Howard et al. (2011c)

26 Hot Jupiters: % - Kepler 1.2 +/- 0.2% - Doppler Different stellar samples? Howard et al. (2011c)

27 Planet Occurrence vs. Stellar Temperature Number of Planets per Star with P < 50 days stars 1761 stars 6009 stars stars stars stars 2299 stars M0 K5 K2 K0 G8 G5 G2 G0 F8 F5 F R E 2 4 R E 4 8 R E 8 32 R E Stellar Effective Temperature, T eff (K) Howard et al. (2011c)

28 Planet Occurrence vs. M Occurrence within 0.25 AU of small planets decreases with M Occurrence within 2.5 AU of giant planets increases with M Howard et al. (2011c) Johnson et al. (2010)

29 Take Home Message: Planet Occurrence ï d2f/dlogp/dlogrp Planet Occurrence ï fcell 32 1 (9) Planet Radius, Rp (RE) (2) (4) (15) (52) (39) (69) (15) (28) (6) (34) (25) (15) (70) (154) (6) (9) (73) (74) (31) (160) (278) (45) (18) (60) (153) (208) (198) (20) (104) (21) (25) (168) (353) (607) (591) (799) (64) (269) (521) (893) (1101) (749) (5) (17) (85) (262) (159) (375) (410) (295) (10) (10) (50) (59) (18) (85) (41) (11) Number of Planets per Star with P < 50 days Orbital Period, P (days) Planet Radius (RE)

30 Take Home Message: Planet Occurrence ï d2f/dlogp/dlogrp Planet Occurrence ï fcell 32 1 (9) Planet Radius, Rp (RE) Small Planets are Common (2) (4) (15) (52) (39) (69) (15) (28) (6) (34) (25) (15) (70) (154) (6) (9) (73) (74) (31) (160) (278) (45) (18) (60) (153) (208) (198) (20) (104) (21) (25) (168) (353) (607) (591) (799) (64) (269) (521) (893) (1101) (749) (5) (17) (85) (262) (159) (375) (410) (295) (10) (10) (50) (59) (18) (85) (41) (11) Number of Planets per Star with P < 50 days Orbital Period, P (days) Planet Radius (RE)

31 QuesXons?