A super-Earth and a mini-Neptune near the 2:1 MMR straddling the radius valley around the nearby mid-M dwarf TOI-2096

Abstract

Several planetary formation models have been proposed to explain the observed abundance and variety of compositions of super-Earths and mini-Neptunes. In this context, multitransiting systems orbiting low-mass stars whose planets are close to the radius valley are benchmark systems, which help to elucidate which formation model dominates. We report the discovery, validation, and initial characterization of one such system, TOI-2096, composed of a super-Earth and a mini-Neptune hosted by a mid-type M dwarf located 48 pc away. We first characterized the host star by combining different methods. Then, we derived the planetary properties by modeling the photometric data from TESS and ground-based facilities. We used archival data, high-resolution imaging, and statistical validation to support our planetary interpretation. We found that TOI-2096 corresponds to a dwarf star of spectral type M4. It harbors a super-Earth (R$\sim 1.2R_{\oplus }$) and a mini-Neptune (R$\sim 1.90R_{\oplus }$) in likely slightly eccentric orbits with orbital periods of 3.12 d and 6.39 d, respectively. These orbital periods are close to the first-order 2:1 mean-motion resonance (MMR), which may lead to measurable transit timing variations (TTVs). We computed the expected TTVs amplitude for each planet and found that they might be measurable with high-precision photometry delivering mid-transit times with accuracies of $\lesssim$2 min. Moreover, measuring the planetary masses via radial velocities (RVs) is also possible. Lastly, we found that these planets are among the best in their class to conduct atmospheric studies using the James Webb Space Telescope (JWST). The properties of this system make it a suitable candidate for further studies, particularly for mass determination using RVs and/or TTVs, decreasing the scarcity of systems that can be used to test planetary formation models around low-mass stars.

arXiv comment25 pages, 21 figures. Aceptted for publication in Astronomy & Astrophysics

References in corpus (159)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• emcee: The MCMC Hammer
• The Sloan Digital Sky Survey: Technical Summary
• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• 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
• Understanding the Lomb-Scargle Periodogram
• Las Cumbres Observatory Global Telescope Network
• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• The false positive rate of Kepler and the occurrence of planets
• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• Importance Nested Sampling and the MultiNest Algorithm
• Towards a Deterministic Model of Planetary Formation I: a Desert in the Mass and Semi Major Axis Distributions of Extra Solar Planets
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• On the Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve
• On detecting terrestrial planets with timing of giant planet transits
• DHP Framework: Digital Health Passports Using Blockchain -- Use case on international tourism during the COVID-19 pandemic
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• Kepler planets: a tale of evaporation
• Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates
• The TESS Input Catalog and Candidate Target List
• 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 (Expanded Edition)
• AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• Temperate Earth-sized planets transiting a nearby ultracool dwarf star
• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Constraining the Age-Activity Relation for Cool Stars: The SDSS DR5 Low-Mass Star Spectroscopic Sample
• Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
• The Mass-Radius Relation for 65 Exoplanets Smaller than 4 Earth Radii
• Extrasolar planet population synthesis I: Method, formation tracks and mass-distance distribution
• The Second-Generation Guide Star Catalog: Description and Properties
• 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
• The Role of Core Mass in Controlling Evaporation: the Kepler Radius Distribution and the Kepler-36 Density Dichotomy
• Core-powered mass loss and the radius distribution of small exoplanets
• Quantifying the Uncertainty in the Orbits of Extrasolar Planets
• WHFast: A fast and unbiased implementation of a symplectic Wisdom-Holman integrator for long term gravitational simulations
• The Minimum-Mass Extrasolar Nebula: In-Situ Formation of Close-In Super-Earths
• Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
• Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
• The TESS Objects of Interest Catalog from the TESS Prime Mission
• How to Constrain Your M dwarf II: the mass-luminosity-metallicity relation from 0.075 to 0.70$M_{\odot }$
• Extracting Planet Mass and Eccentricity From TTV data
• The California-Kepler Survey. I. High Resolution Spectroscopy of 1305 Stars Hosting Kepler Transiting Planets
• Kepler Data Validation I -- Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
• Almost All of Kepler's Multiple Planet Candidates are Planets
• Density, not radius, separates rocky and water-rich small planets orbiting M dwarf stars
• Low-Mass Dwarf Template Spectra from the Sloan Digital Sky Survey
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks
• Compositional imprints in density-distance-time: a rocky composition for close-in low-mass exoplanets from the location of the valley of evaporation
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• Formation and Structure of Low Density Exo-Neptunes
• Make Super-Earths, Not Jupiters: Accreting Nebular Gas onto Solid Cores at 0.1 AU and Beyond
• A Spectroscopic Catalog of the Brightest (J<9) M Dwarfs in the Northern Sky
• About 30% of Sun-like Stars Have Kepler-like Planetary Systems: A Study of their Intrinsic Architecture
• Testing In Situ Assembly with the Kepler Planet Candidate Sample
• Planetary nebulae seen with TESS: Discovery of new binary central star candidates from Cycle 1
• The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres
• Transit Least Squares: Optimized transit detection algorithm to search for periodic transits of small planets
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• Revisited Mass-Radius relations for exoplanets below 120 Earth masses
• Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844b
• The coronal X-ray - age relation and its implications for the evaporation of exoplanets
• Wotan: Comprehensive time-series de-trending in Python
• Stellar Winds on the Main-Sequence II: the Evolution of Rotation and Winds
• Ocean Planet or Thick Atmosphere: On the Mass-Radius Relationship for Solid Exoplanets with Massive Atmospheres
• Characterizing the Cool KOIs III. KOI-961: A Small Star with Large Proper Motion and Three Small Planets
• Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM)
• 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
• Prospecting in late-type dwarfs: a calibration of infrared and visible spectroscopic metallicities of late-K and M dwarfs spanning 1.5 dex
• Six transiting planets and a chain of Laplace resonances in TOI-178
• The Gaia-Kepler Stellar Properties Catalog. II. Planet Radius Demographics as a Function of Stellar Mass and Age
• Spectroscopy of New High Proper Motion Stars in the Northern Sky. I. New Nearby Stars, New High Velocity Stars, and an Enhanced Classification Scheme for M Dwarfs
• Empirical, Accurate Masses and Radii of Single Stars with TESS and Gaia
• The California-Kepler Survey. II. Precise Physical Properties of 2025 Kepler Planets and Their Host Stars
• Evolution of the radius valley around low mass stars from $Kepler$ and $K2$
• Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates
• ELLC - a fast, flexible light curve model for detached eclipsing binary stars and transiting exoplanets
• 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 ${\eta }_{\oplus }$
• Constraining Exoplanet Mass from Transmission Spectroscopy
• The nature and origins of sub-Neptune size planets
• Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton
• TRAPPIST: a robotic telescope dedicated to the study of planetary systems
• The 10 parsec sample in the Gaia era
• The L 98-59 System: Three Transiting, Terrestrial-Sized Planets Orbiting a Nearby M-dwarf
• Atmosphere Origins for Exoplanet Sub-Neptunes
• Mass and Mass Scalings of Super-Earths
• A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270
• Synthesizing Exoplanet Demographics from Radial Velocity and Microlensing Surveys, II: The Frequency of Planets Orbiting M Dwarfs
• A Definition for Giant Planets Based on the Mass-Density Relationship
• The (In)Stability of Planetary Systems
• An Updated Study of Potential Targets for Ariel
• An empirical template library of stellar spectra for a wide range of spectral classes, luminosity classes, and metallicities using SDSS BOSS spectra
• Predicting the long-term stability of compact multiplanet systems
• Migration-driven diversity of super-Earth compositions
• SPECULOOS -- Ultracool Dwarf Transit Survey: Target List and Strategy
• A super-Earth and a sub-Neptune orbiting the bright, quiet M3 dwarf TOI-1266
• Architectures of Exoplanetary Systems. III: Eccentricity and Mutual Inclination Distributions of AMD-stable Planetary Systems
• A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780
• Homogeneous Analysis of Hot Earths: Masses, Sizes, and Compositions
• Exoplanets around Low-mass Stars Unveiled by K2
• Transit detection of the long-period volatile-rich super-Earth ${\nu }^2$ Lupi d with $CHEOPS$
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope IV. Capabilities and predicted performance for exoplanet characterization
• Stellar parameters for TRAPPIST-1
• Primordial Radius Gap and Potentially Broad Core Mass Distributions of Super-Earths and Sub-Neptunes
• Theoretical Examination of the Lithium Depletion Boundary
• The Exoplanet Orbital Eccentricity - Multiplicity Relation and the Solar System
• Testing exoplanet evaporation with multi-transiting systems
• Two temperate super-Earths transiting a nearby late-type M dwarf
• Optical Spectroscopic Classification and Membership of Young M Dwarfs in Star-Forming Regions
• Speckle Imaging Excludes Low-Mass Companions Orbiting the Exoplanet Host Star TRAPPIST-1
• prose: A Python framework for modular astronomical images processing
• A super-Earth and sub-Neptune transiting the late-type M dwarf LP 791-18
• Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
• ArielRad: the Ariel Radiometric Model
• TOI-1452 b: SPIRou and TESS reveal a super-Earth in a temperate orbit transiting an M4 dwarf
• No Conclusive Evidence for Transits of Proxima b in MOST photometry
• Refined Metallicity Indices for M Dwarfs Using the SLoWPoKES Catalog of Wide, Low-mass Binaries
• Pebbles versus planetesimals: the outcomes of population synthesis models
• GJ 273: On the formation, dynamical evolution and habitability of a planetary system hosted by an M dwarf at 3.75 parsec
• The Ariel Target List: The Impact of TESS and the Potential for Characterising Multiple Planets Within a System
• A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
• Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
• Predicting a third planet in the Kepler-47 circumbinary system
• Orbital Dynamics of Multi-Planet Systems with Eccentricity Diversity
• Behavior of Apsidal Orientations in Planetary Systems
• Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?
• Close-in sub-Neptunes reveal the past rotation history of their host stars: atmospheric evolution of planets in the HD3167 and K2-32 planetary systems
• TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
• Arid or Cloudy: Characterizing the Atmosphere of the super-Earth 55 Cancri e using High-Resolution Spectroscopy
• An ultra-short-period transiting super-Earth orbiting the M3 dwarf TOI-1685
• Near-resonance in a system of sub-Neptunes from TESS
• Energy Optimization in Extrasolar Planetary Systems: The Transition from Peas-in-a-Pod to Runaway Growth
• K2-146: Discovery of Planet c, Precise Masses from Transit Timing, and Observed Precession
• Evolutionary models for ultracool dwarfs
• SPECULOOS Northern Observatory: searching for red worlds in the northern skies
• Anti-correlation between multiplicity and orbital properties in exoplanetary systems as a possible record of their dynamical histories
• A transit survey to search for planets around hot subdwarfs: I. methods and performance tests on light curves from Kepler, K2, TESS, and CHEOPS
• EDEN: Sensitivity Analysis and Transiting Planet Detection Limits for Nearby Late Red Dwarfs
• GJ357: A low-mass planetary system uncovered by precision radial-velocities and dynamical simulations
• TOI-532b: The Habitable-zone Planet Finder confirms a Large Super Neptune in the Neptune Desert orbiting a metal-rich M dwarf host
• M subdwarf research. I. Identification, modified classification system, and sample construction
• Orbital Stability and Precession Effects in the Kepler-89 System
• It takes two planets in resonance to tango around K2-146
• TOI-1075 b: A Dense, Massive, Ultra-Short Period Hot Super-Earth Straddling the Radius Gap
• A Super-Earth Orbiting Near the Inner Edge of the Habitable Zone around the M4.5-dwarf Ross 508
• TOI 122b and TOI 237b, two small warm planets orbiting inactive M dwarfs, found by \textit{TESS}
• $\pi$ Earth: a 3.14-day Earth-sized Planet from $\text{K2}$'s Kitchen Served Warm by the SPECULOOS Team

Cited by in corpus (15)

• Two super-Earths at the edge of the habitable zone of the nearby M dwarf TOI-2095
• The SHERLOCK pipeline: new exoplanet candidates in the WASP-16, HAT-P-27, HAT-P-26, and TOI-2411 systems
• TOI-4438 b: a transiting mini-Neptune amenable to atmospheric characterization
• Refining the properties of the TOI-178 system with CHEOPS and TESS
• TESS discovery of two super-Earths orbiting the M-dwarf stars TOI-6002 and TOI-5713 near the radius valley
• Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration
• A transiting giant planet in orbit around a 0.2-solar-mass host star
• TOI-4336 A b: A temperate sub-Neptune ripe for atmospheric characterization in a nearby triple M-dwarf system
• Two warm Earth-sized exoplanets and an Earth-sized candidate in the M5V-M6V binary system TOI-2267
• TOI-1743 b, TOI-5799 b, TOI-5799 c and TOI-6223 b: TESS discovery and validation of four super-Earth to Neptune-sized planets around M dwarfs
• Earth-like planet predictor: A machine learning approach
• TOI-7166 b: A Habitable Zone mini-Neptune planet around a nearby low-mass star
• A transiting rocky super-Earth and a non-transiting sub-Neptune orbiting the M dwarf TOI-771
• Sibling Sub-Neptunes Around Sibling M Dwarfs: TOI-521 and TOI-912
• Hidden Gems in TESS: sherlock finds two new rocky planets around nearby M dwarfs