Know the Planet, Know the Star: Precise Stellar Densities from Kepler Transit Light Curves

Abstract

The properties of a transiting planet's host star are written in its transit light curve. The light curve can reveal the stellar density and the limb darkening profile in addition to the characteristics of the planet and its orbit. For planets with strong prior constraints on orbital eccentricity, we may measure these stellar properties directly from the light curve; this method promises to aid greatly in the characterization of transiting planet host stars targeted by the upcoming NASA TESS mission and any long-period, singly-transiting planets discovered in the same systems. Using Bayesian inference, we fit a transit model, including a nonlinear limb darkening law, to 66 Kepler transiting planet hosts to measure their stellar properties. We present posterior distributions of stellar density, limb-darkening coefficients, and other system parameters for these stars. We measure densities to within 5% for the majority of our target stars, with the dominant precision-limiting factor being the signal-to-noise ratio of the transits. 95 % of our measured stellar densities are in 3-sigma or better agreement with previously published literature values. We make posterior distributions for all of our target KOIs available for online download.

Accepted to AJ; 19 pages, 12 figures; posteriors available for download at https://github.com/esandford/KnowThePlanet

References in corpus (42)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Habitable Zones Around Main-Sequence Stars: New Estimates
• batman: BAsic Transit Model cAlculatioN in Python
• Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data
• On the Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve
• A map of the day-night contrast of the extrasolar planet HD 189733b
• A Closely-Packed System of Low-Mass, Low-Density Planets Transiting Kepler-11
• The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives
• Quantifying the Uncertainty in the Orbits of Extrasolar Planets
• False positive probabilties for all Kepler Objects of Interest: 1284 newly validated planets and 428 likely false positives
• Tidal dissipation in rotating giant planets
• Kepler-47: A Transiting Circumbinary Multi-Planet System
• Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology
• Parametrizing the exoplanet eccentricity distribution with the Beta distribution
• Eccentricity from transit photometry: small planets in Kepler multi-planet systems have low eccentricities
• Revised Stellar Properties of Kepler Targets for the Q1-17 (DR25) Transit Detection Run
• Stellar Limb-Darkening Coefficients for CoRot and Kepler
• Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
• Using Stellar Limb-Darkening to Refine the Properties of HD 209458b
• Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models
• EVEREST: Pixel Level Decorrelation of K2 Light curves
• Transit Timing Observations from Kepler. IX. Catalog of the Full Long-Cadence Data Set
• The hot-Jupiter Kepler-17b: discovery, obliquity from stroboscopic starspots, and atmospheric characterization
• K2SC: Flexible systematics correction and detrending of K2 light curves using Gaussian Process regression
• TrES-2: The First Transiting Planet in the Kepler Field
• Analytic Approximations for Transit Light Curve Observables, Uncertainties, and Covariances
• The asteroseismic potential of TESS: exoplanet-host stars
• Investigations of approximate expressions for the transit duration
• HEK VI: On the Dearth of Galilean Analogs in Kepler and the Exomoon Candidate Kepler-1625b I
• Transiting planets - lightcurve analysis for eccentric orbits
• A Uniform Search for Secondary Eclipses of Hot Jupiters in Kepler Q2 Lightcurves
• Analysis of Kepler's short-cadence photometry for TrES-2b
• Detection of Planetary Emission from the Exoplanet TrES-2 using Spitzer /IRAC
• On the Eccentricity Distribution of Short-Period Single-Planet Systems
• APOSTLE Observations of GJ 1214b: System Parameters and Evidence for Stellar Activity
• Observational biases for transiting planets
• The Eccentricity Distribution of Short-Period Planet Candidates Detected by Kepler in Occultation
• Characterizing Long-Period Transiting Planets Observed by Kepler
• It takes a village to raise a tide: nonlinear multiple-mode coupling and mode identification in KOI-54
• Efficient, uninformative sampling of limb-darkening coefficients for a three-parameter law
• A Quintuple Star System Containing Two Eclipsing Binaries

Cited by in corpus (21)

• High Tide or Riptide on the Cosmic Shoreline? A Water-Rich Atmosphere or Stellar Contamination for the Warm Super-Earth GJ~486b from JWST Observations
• A JWST transmission spectrum of a nearby Earth-sized exoplanet
• An Exomoon Survey of 70 Cool Giant Exoplanets and the New Candidate Kepler-1708 b-i
• Empirical limb-darkening coefficients & transit parameters of known exoplanets from TESS
• The Impact of Stellar Distances on Habitable Zone Planets
• Diffuser-assisted Photometric Follow-up Observations of the Neptune-sized Planets K2-28b and K2-100b
• Kepler's Dark Worlds: a Low Albedo for an Ensemble of Neptunian and Terran Exoplanets
• Beating stellar systematic error floors using transit-based densities
• A warm super-Neptune around the G-dwarf star TOI-1710 revealed with TESS, SOPHIE and HARPS-N
• The TESS-Keck Survey. VI. Two Eccentric sub-Neptunes Orbiting HIP-97166
• First Comparative Exoplanetology Within a Transiting Multi-planet System: Comparing the atmospheres of V1298 Tau b and c
• Wolf 503 b: Characterization of a Sub-Neptune Orbiting a Metal-Poor K Dwarf
• Estimation of singly-transiting K2 planet periods with Gaia parallaxes
• The Telltale Heartbeat: Detection and Characterization of Eccentric Orbiting Planets via Tides on their Host Star
• The TESS-Keck Survey. XIII. An Eccentric Hot Neptune with a Similar-Mass Outer Companion around TOI-1272
• Analytic Estimates of the Achievable Precision on the Physical Properties of Transiting Planets Using Purely Empirical Measurements
• Ages for exoplanet host stars
• A homogeneous TTV investigation of all TESS systems with a confirmed single transiting planet
• Kepler Bonus: Aperture Photometry Light Curves of EXBA Sources
• Using asteroseismology to characterise exoplanet host stars
• A search for transits among the δ Scuti variables in Kepler