TOI-1634 b: an Ultra-Short Period Keystone Planet Sitting Inside the M Dwarf Radius Valley
arXiv:2103.12790 · doi:10.3847/1538-3881/ac0157
Abstract
Studies of close-in planets orbiting M dwarfs have suggested that the M dwarf radius valley may be well-explained by distinct formation timescales between enveloped terrestrials, and rocky planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseous envelope that is subsequently stripped away by some thermally-driven mass loss process. These two physical scenarios make unique predictions of the rocky/enveloped transition's dependence on orbital separation such that studying the compositions of planets within the M dwarf radius valley may be able to establish the dominant physics. Here, we present the discovery of one such keystone planet: the ultra-short period planet TOI-1634 b ( days, , ) orbiting a nearby M2 dwarf (, , ) and whose size and orbital period sit within the M dwarf radius valley. We confirm the TESS-discovered planet candidate using extensive ground-based follow-up campaigns, including a set of 32 precise radial velocity measurements from HARPS-N. We measure a planetary mass of , which makes TOI-1634 b inconsistent with an Earth-like composition at and thus requires either an extended gaseous envelope, a large volatile-rich layer, or a rocky portion that is not dominated by iron and silicates to explain its mass and radius. The discovery that the bulk composition of TOI-1634 b is inconsistent with that of the Earth favors the gas-depleted formation mechanism to explain the emergence of the radius valley around M dwarfs with .
arXiv comment27 pages, 13 figures, accepted to AAS journals. Our time series are included as a csv file in the arXiv source files
References in corpus (116)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- Astropy: A Community Python Package for Astronomy
- emcee: The MCMC Hammer
- The Transiting Exoplanet Survey Satellite
- Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
- Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
- Analytic Lightcurves for Planetary Transit Searches
- Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
- The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
- Habitable Zones Around Main-Sequence Stars: New Estimates
- Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
- The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
- Las Cumbres Observatory Global Telescope Network
- Gaia Early Data Release 3: The astrometric solution
- batman: BAsic Transit Model cAlculatioN in Python
- Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
- Fast and scalable Gaussian process modeling with applications to astronomical time series
- The Revised TESS Input Catalog and Candidate Target List
- Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
- Gaia Early Data Release 3: Photometric content and validation
- Kepler planets: a tale of evaporation
- The evaporation valley in the Kepler planets
- Gaia Data Release 2: Photometric content and validation
- EXOFAST: A fast exoplanetary fitting suite in IDL
- How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
- Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
- AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves
- AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves (Expanded Edition)
- The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample
- A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
- The California Kepler Survey VII. Precise Planet Radii Leveraging Gaia DR2 Reveal the Stellar Mass Dependence of the Planet Radius Gap
- An asteroseismic view of the radius valley: stripped cores, not born rocky
- Core-powered mass loss and the radius distribution of small exoplanets
- Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
- The NextGen Model Atmosphere grid: II. Spherically symmetric model atmospheres for giant stars with effective temperatures between 3000 and 6800~K
- Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
- The MUSCLES Treasury Survey I: Motivation and Overview
- The HARPS-TERRA project I. Description of the algorithms, performance and new measurements on a few remarkable stars observed by HARPS
- HAT-P-16b: A 4 Mj Planet Transiting A Bright Star On An Eccentric Orbit
- The H emission of nearby M dwarfs and its relation to stellar rotation
- Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
- A temperate rocky super-Earth transiting a nearby cool star
- Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
- STARRY: Analytic Occultation Light Curves
- Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
- PandExo: A Community Tool for Transiting Exoplanet Science with JWST & HST
- Kepler Data Validation I -- Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
- Parametrizing the exoplanet eccentricity distribution with the Beta distribution
- A new list of thorium and argon spectral lines in the visible
- Compositional imprints in density-distance-time: a rocky composition for close-in low-mass exoplanets from the location of the valley of evaporation
- The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres
- A Detailed Model Grid for Solid Planets from 0.1 through 100 Earth Masses
- Real-time processing of the imaging data from the network of Las Cumbres Observatory Telescopes using BANZAI
- Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
- Evidence for Magnetic Flux Saturation in Rapidly Rotating M Stars
- Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
- A rocky planet transiting a nearby low-mass star
- Evolutionary Analysis of Gaseous Sub-Neptune-Mass Planets with MESA
- The Solar Neighborhood XXXVII: The Mass-Luminosity Relation for Main Sequence M Dwarfs
- Eclipsing Binary Stars as Benchmarks for Trigonometric Parallaxes in the Gaia Era
- Signatures of the Core-Powered Mass-Loss Mechanism in the Exoplanet Population: Dependence on Stellar Properties and Observational Predictions
- They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets
- On the Metal-Richness of M Dwarfs with Planets
- Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
- Kepler Planet Occurrence Rates for Mid-Type M Dwarfs as a Function of Spectral Type
- Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
- Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets
- The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
- Evolution of the radius valley around low mass stars from and
- Born Dry in the Photo-Evaporation Desert: Kepler's Ultra-Short-Period Planets Formed Water-Poor
- Predictions of the atmospheric composition of GJ 1132b
- TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844
- HAZMAT I: The Evolution of Far-UV and Near-UV Emission from Early M Stars
- Minimum Radii of Super-Earths: Constraints from Giant Impacts
- The Kepler Dichotomy among the M Dwarfs: Half of Systems Contain Five or More Coplanar Planets
- How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for
- Forward and Inverse Modeling of the Emission and Transmission Spectrum of GJ 436b: Investigating Metal Enrichment, Tidal Heating, and Clouds
- The Distribution of Transit Durations for Kepler Planet Candidates and Implications for their Orbital Eccentricities
- BGLS: A Bayesian formalism for the generalised Lomb-Scargle periodogram
- The Photoeccentric Effect and Proto-Hot Jupiters I. Measuring photometric eccentricities of individual transiting planets
- Quantifying and Predicting the Presence of Clouds in Exoplanet Atmospheres
- The 55 Cnc system reassessed
- Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
- Mass and Mass Scalings of Super-Earths
- A Spectroscopic Analysis of the California-Kepler Survey Sample: I. Stellar Parameters, Planetary Radii and a Slope in the Radius Gap
- Kepler-445, Kepler-446 and the Occurrence of Compact Multiples Orbiting Mid-M Dwarf Stars
- Exoplanet secondary atmosphere loss and revival
- A second terrestrial planet orbiting the nearby M dwarf LHS 1140
- A new class of Super-Earths formed from high-temperature condensates: HD219134 b, 55 Cnc e, WASP-47 e
- A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780
- Separating planetary reflex Doppler shifts from stellar variability in the wavelength domain
- Statistical Analysis of Hubble/WFC3 Transit Spectroscopy of Extrasolar Planets
- Homogeneous Analysis of Hot Earths: Masses, Sizes, and Compositions
- The HARPS search for southern extra-solar planets XXXV. Planetary systems and stellar activity of the M dwarfs GJ 3293, GJ 3341, and GJ 3543
- Multicolour photometry for exoplanet candidate validation
- Primordial Radius Gap and Potentially Broad Core Mass Distributions of Super-Earths and Sub-Neptunes
- Identifying Atmospheres on Rocky Exoplanets Through Inferred High Albedo
- MuSCAT2: four-color Simultaneous Camera for the 1.52-m Telescopio Carlos Sánchez
- Characterization of the L 98-59 multi-planetary system with HARPS: two confirmed terrestrial planets and a mass upper limit on the third
- Kepler Exoplanet Candidate Host Stars are Preferentially Metal Rich
- Confirmation of the radial velocity super-Earth K2-18c with HARPS and CARMENES
- Radial velocity follow-up of GJ1132 with HARPS. A precise mass for planet 'b' and the discovery of a second planet
- Precise Masses in the WASP-47 System
- Analyzing Atmospheric Temperature Profiles and Spectra of M dwarf Rocky Planets
- MuSCAT2 multicolour validation of TESS candidates: an ultra-short-period substellar object around an M dwarf
- Gaia Search for stellar Companions of TESS Objects of Interest
- A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
- Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?
- A Closer Look at Exoplanet Occurrence Rates: Considering the Multiplicity of Stars Without Detected Planets
- TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
- An ultra-short-period transiting super-Earth orbiting the M3 dwarf TOI-1685
- Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
- Astraea: Predicting Long Rotation Periods with 27-Day Light Curves
- LHS 1610A: A Nearby Mid-M Dwarf with a Companion That is Likely A Brown Dwarf
- Chaotic Excitation and Tidal Damping in the GJ 876 System
- Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler