Testing exoplanet evaporation with multi-transiting systems

Abstract

The photoevaporation model is one of the leading explanations for the evolution of small, close-in planets and the origin of the radius-valley. However, without planet mass measurements, it is challenging to test the photoevaporation scenario. Even if masses are available for individual planets, the host star's unknown EUV/X-ray history makes it difficult to assess the role of photoevaporation. We show that systems with multiple transiting planets are the best in which to rigorously test the photoevaporation model. By scaling one planet to another in a multi-transiting system, the host star's uncertain EUV/X-ray history can be negated. By focusing on systems that contain planets that straddle the radius-valley, one can estimate the minimum-masses of planets above the radius-valley (and thus are assumed to have retained a voluminous hydrogen/helium envelope). This minimum-mass is estimated by assuming that the planet below the radius-valley entirely lost its initial hydrogen/helium envelope, then calculating how massive any planet above the valley needs to be to retain its envelope. We apply this method to 104 planets above the radius gap in 73 systems for which precise enough radii measurements are available. We find excellent agreement with the photoevaporation model. Only two planets (Kepler - 100c & 142c) appear to be inconsistent, suggesting they had a different formation history or followed a different evolutionary pathway to the bulk of the population. Our method can be used to identify TESS systems that warrant radial-velocity follow-up to further test the photoevaporation model.

Accepted for publication in MNRAS. The software to estimate minimum planet masses is publicly available at: https://github.com/jo276/EvapMass

References in corpus (22)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Most 1.6 Earth-Radius Planets are not Rocky
• Atmospheric Escape from Hot Jupiters
• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• Growth Model Interpretation of Planet Size Distribution
• A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
• Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
• Detailed Models of super-Earths: How well can we infer bulk properties?
• The Extreme Ultraviolet and X-Ray Sun in Time: High-Energy Evolutionary Tracks of a Solar-Like Star
• The Mass of Kepler-93b and The Composition of Terrestrial Planets
• A Statistical Reconstruction of the Planet Population Around Kepler Solar-Type Stars
• A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system
• A new class of Super-Earths formed from high-temperature condensates: HD219134 b, 55 Cnc e, WASP-47 e
• Accounting for Incompleteness due to Transit Multiplicity in Kepler Planet Occurrence Rates
• A 1.9 Earth radius rocky planet and the discovery of a non-transiting planet in the Kepler-20 system
• Susceptibility of planetary atmospheres to mass loss and growth by planetesimal impacts: the impact shoreline
• Long-Period Giant Companions to Three Compact, Multiplanet Systems
• Pinning down the mass of Kepler-10c: the importance of sampling and model comparison
• Effects of Magnetic Fields on the Location of the Evaporation Valley for Low-Mass Exoplanets
• Characterization of the Kepler-101 planetary system with HARPS-N. A hot super-Neptune with an Earth-sized low-mass companion
• Close-in Super-Earths: The first and the last stages of planet formation in an MRI-accreting disc
• A New Yield Simulator for Transiting Planets and False Positives: Application to the Next Generation Transit Survey

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• CHEOPS observations of the HD 108236 planetary system: A fifth planet, improved ephemerides, and planetary radii
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• TOI-1136 is a Young, Coplanar, Aligned Planetary System in a Pristine Resonant Chain
• Hydrogen dominated atmospheres on terrestrial mass planets: evidence, origin and evolution
• The Kepler Giant Planet Search. I: A Decade of Kepler Planet-host Radial Velocities from W. M. Keck Observatory
• Current Population Statistics Do Not Favor Photoevaporation over Core-Powered Mass Loss as the Dominant Cause of the Exoplanet Radius Gap
• Coupling thermal evolution of planets and hydrodynamic atmospheric escape in MESA
• A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
• TOI-2076 and TOI-1807: Two young, comoving planetary systems within 50 pc identified by TESS that are ideal candidates for further follow-up
• Constraining the entropy of formation from young transiting planets
• TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
• AU Microscopii in the FUV: Observations in Quiescence, During Flares, and Implications for AU Mic b and c
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• The K2-3 system revisited: testing photoevaporation and core-powered mass loss with three small planets spanning the radius valley
• A super-Earth and a mini-Neptune near the 2:1 MMR straddling the radius valley around the nearby mid-M dwarf TOI-2096
• 37 New Validated Planets in Overlapping K2 Campaigns
• TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley
• Scaling K2. IV. A Uniform Planet Sample for Campaigns 1-8 and 10-18
• Unveiling the internal structure and formation history of the three planets transiting HIP 29442 (TOI-469) with CHEOPS
• Physical Parameters of the Multi-Planet Systems HD 106315 and GJ 9827
• TESS discovery of a super-Earth and three sub-Neptunes hosted by the bright, Sun-like star HD 108236
• The shared evaporation history of three sub-Neptunes spanning the radius-period valley of a Hyades star
• On the Orbital Spacing Pattern of Kepler Multiple Planet Systems
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