Abstract
We characterize the eccentricity distribution of a sample of ∼50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is σ = 0.081± 0.003 0.014. We find that a two-component Gaussian mixture model for e cos ω and e sin ω provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that ∼90% of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion (∼0.01), and ∼10% come from a population with a larger dispersion (∼0.22). Finally, we investigate how the eccentricity distribution correlates with selected planet and host star parameters. We find evidence that suggests systems around higher metallicity stars and planet candidates with smaller radii come from a more complex eccentricity distribution.
| Original language | English (US) |
|---|---|
| Article number | 93 |
| Journal | Astrophysical Journal |
| Volume | 820 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 1 2016 |
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All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
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THE ECCENTRICITY DISTRIBUTION of SHORT-PERIOD PLANET CANDIDATES DETECTED by KEPLER in OCCULTATION. / Shabram, Megan; Demory, Brice Olivier; Cisewski, Jessi; Ford, Eric B.; Rogers, Leslie.
In: Astrophysical Journal, Vol. 820, No. 2, 93, 01.04.2016.Research output: Contribution to journal › Article
TY - JOUR
T1 - THE ECCENTRICITY DISTRIBUTION of SHORT-PERIOD PLANET CANDIDATES DETECTED by KEPLER in OCCULTATION
AU - Shabram, Megan
AU - Demory, Brice Olivier
AU - Cisewski, Jessi
AU - Ford, Eric B.
AU - Rogers, Leslie
PY - 2016/4/1
Y1 - 2016/4/1
N2 - We characterize the eccentricity distribution of a sample of ∼50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is σ = 0.081± 0.003 0.014. We find that a two-component Gaussian mixture model for e cos ω and e sin ω provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that ∼90% of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion (∼0.01), and ∼10% come from a population with a larger dispersion (∼0.22). Finally, we investigate how the eccentricity distribution correlates with selected planet and host star parameters. We find evidence that suggests systems around higher metallicity stars and planet candidates with smaller radii come from a more complex eccentricity distribution.
AB - We characterize the eccentricity distribution of a sample of ∼50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is σ = 0.081± 0.003 0.014. We find that a two-component Gaussian mixture model for e cos ω and e sin ω provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that ∼90% of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion (∼0.01), and ∼10% come from a population with a larger dispersion (∼0.22). Finally, we investigate how the eccentricity distribution correlates with selected planet and host star parameters. We find evidence that suggests systems around higher metallicity stars and planet candidates with smaller radii come from a more complex eccentricity distribution.
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U2 - 10.3847/0004-637X/820/2/93
DO - 10.3847/0004-637X/820/2/93
M3 - Article
AN - SCOPUS:84964057070
VL - 820
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 93
ER -