The statistics of multi-planet systems

Abstract

We describe statistical methods for measuring the exoplanet multiplicity function - the fraction of host stars containing a given number of planets - from transit and radial-velocity surveys. The analysis is based on the approximation of separability - that the distribution of planetary parameters in an n-planet system is the product of identical 1-planet distributions. We review the evidence that separability is a valid approximation for exoplanets. We show how to relate the observable multiplicity function in surveys with similar host-star populations but different sensitivities. We also show how to correct for geometrical selection effects to derive the multiplicity function from transit surveys if the distribution of relative inclinations is known. Applying these tools to the Kepler transit survey and radial-velocity surveys, we find that (i) the Kepler data alone do not constrain the mean inclination of multi-planet systems; even spherical distributions are allowed by the data but only if a small fraction of host stars contain large planet populations (> 30); (ii) comparing the Kepler and radial-velocity surveys shows that the mean inclination of multi-planet systems lies in the range 0-5 degrees; (iii) the multiplicity function of the Kepler planets is not well-determined by the present data.

34 pages, 10 figures

References in corpus (13)

• Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data
• Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
• A Closely-Packed System of Low-Mass, Low-Density Planets Transiting Kepler-11
• The Exoplanet Orbit Database
• On the Low False Positive Probabilities of Kepler Planet Candidates
• The Exoplanet Census: A General Method, Applied to Kepler
• A First Comparison of Kepler Planet Candidates in Single and Multiple Systems
• The HARPS search for southern extra-solar planets XIX. Characterization and dynamics of the GJ876 planetary system
• The Distribution of Transit Durations for Kepler Planet Candidates and Implications for their Orbital Eccentricities
• Transit Timing Observations from Kepler: I. Statistical Analysis of the First Four Months
• Orbital structure of the GJ876 extrasolar planetary system, based on the latest Keck and HARPS radial velocity data
• The Origin of the Exoplanets
• The architecture of the GJ876 planetary system. Masses and orbital coplanarity for planets b and c

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