GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation

Abstract

We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of 0.519 $\pm$ 0.013 M${}_{\odot }$ and a radius of 0.516 $\pm$ 0.016 R${}_{\odot }$. We modelled the transit light curves and radial velocity measurements and obtained a planetary mass of 3.34 $\pm$ 0.72 M${}_{\oplus }$, a radius of 2.13 $\pm$ 0.11 R${}_{\oplus }$, and a mean density of 1.89${}_{-0.45}^{+0.52}$ g/cm${}^3$. The low density of the planet implies the presence of volatiles, and its radius and insolation place it immediately above the radius valley at the lower end of the mini-Neptune cluster. A coupled atmospheric and dynamical evolution analysis of the planet is inconsistent with a pure H-He atmosphere and favours a heavy mean molecular weight atmosphere. The transmission spectroscopy metric of 221${}_{-46}^{+66}$ means that GJ 3090 b is the second or third most favourable mini-Neptune after GJ 1214 b whose atmosphere may be characterised. At almost half the mass of GJ 1214 b, GJ 3090 b is an excellent probe of the edge of the transition between super-Earths and mini-Neptunes. We identify an additional signal in the radial velocity data that we attribute to a planet candidate with an orbital period of 13 days and a mass of 17.1${}_{-3.2}^{+8.9}$ M${}_{\oplus }$, whose transits are not detected.

arXiv comment25 pages, 26 figures, accepted for publication in A&A

References in corpus (129)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• The Transiting Exoplanet Survey Satellite
• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• Analytic Lightcurves for Planetary Transit Searches
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• The James Webb Space Telescope
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Detection of Planetary Transits Across a Sun-like Star
• The WASP Project and the SuperWASP Cameras
• Las Cumbres Observatory Global Telescope Network
• Gaia Early Data Release 3: The astrometric solution
• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• 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
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• Gaia Early Data Release 3: Photometric content and validation
• A super-Earth transiting a nearby low-mass star
• The evaporation valley in the Kepler planets
• The chemical make-up of the Sun: A 2020 vision
• 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)
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
• Growth Model Interpretation of Planet Size Distribution
• petitRADTRANS: a Python radiative transfer package for exoplanet characterization and retrieval
• RadVel: The Radial Velocity Modeling Toolkit
• An asteroseismic view of the radius valley: stripped cores, not born rocky
• Core-powered mass loss and the radius distribution of small exoplanets
• Roche lobe effects on the atmospheric loss of "Hot Jupiters"
• WHFast: A fast and unbiased implementation of a symplectic Wisdom-Holman integrator for long term gravitational simulations
• Evolution in Binary and Triple Stars, with an application to SS Lac
• 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
• Characterizing transiting exoplanet atmospheres with JWST
• How to Constrain Your M dwarf II: the mass-luminosity-metallicity relation from 0.075 to 0.70$M_{\odot }$
• Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
• Dearth of short-period Neptunian exoplanets - a desert in period-mass and period-radius planes
• Can we constrain interior structure of rocky exoplanets from mass and radius measurements?
• Juliet: a versatile modelling tool for transiting and non-transiting exoplanetary systems
• Planetary Spectrum Generator: an accurate online radiative transfer suite for atmospheres, comets, small bodies and exoplanets
• 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
• Binning is sinning: morphological light-curve distortions due to finite integration time
• Precision Stellar Characterization of FGKM Stars using an Empirical Spectral Library
• Water Vapor and Clouds on the Habitable-Zone Sub-Neptune Exoplanet K2-18b
• A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster
• Water vapour in the atmosphere of the habitable-zone eight Earth-mass planet K2-18 b
• Compositional imprints in density-distance-time: a rocky composition for close-in low-mass exoplanets from the location of the valley of evaporation
• Hot super-Earths stripped by their host stars
• A diagram for the evaporation status of extrasolar planets
• Planetary nebulae seen with TESS: Discovery of new binary central star candidates from Cycle 1
• Thermal Emission and Albedo Spectra of Super Earths with Flat Transmission Spectra
• Three Possible Origins for the Gas Layer on GJ 1214b
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• Revisited Mass-Radius relations for exoplanets below 120 Earth masses
• The coronal X-ray - age relation and its implications for the evaporation of exoplanets
• SOAR TESS Survey. I: Sculpting of TESS planetary systems by stellar companions
• Aerosol Composition of Hot Giant Exoplanets Dominated by Silicates and Hydrocarbon Hazes
• Quantitatively Assessing the Role of Clouds in the Transmission Spectrum of GJ 1214b
• A short-period censor of sub-Jupiter mass exoplanets with low density
• A generalized bayesian inference method for constraining the interiors of super Earths and sub-Neptunes
• The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultra-Short Periods
• Bulk Composition of GJ 1214b and other sub-Neptune exoplanets
• PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance
• Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• Ten years of speckle interferometry at SOAR
• Emerging Trends in a Period-Radius Distribution of Close-in Planets
• The Chemical Homogeneity of Sun-like Stars in the Solar Neighborhood
• Angular Momentum Loss from Cool Stars: An Empirical Expression and Connection to Stellar Activity
• Born Dry in the Photo-Evaporation Desert: Kepler's Ultra-Short-Period Planets Formed Water-Poor
• Evolution of the radius valley around low mass stars from $Kepler$ and $K2$
• The HARPS search for southern extra-solar planets XLI. A dozen planets around the M dwarfs GJ 3138, GJ 3323, GJ 273, GJ 628, and GJ 3293
• How stellar activity affects the size estimates of extrasolar planets
• A non-grey analytical model for irradiated atmospheres. I: Derivation
• AQUA: A Collection of H${}_2$O Equations of State for Planetary Models
• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• Orbital misalignment of the Neptune-mass exoplanet GJ 436b with the spin of its cool star
• Energy-limited escape revised
• WASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V star
• Irradiated ocean planets bridge super-Earth and sub-Neptune populations
• 3D modeling of GJ1214b's atmosphere: formation of inhomogeneous high clouds and observational implications
• A new ab initio equation of state of hcp-Fe and its implication on the interior structure and mass-radius relations of rocky super-Earths
• Effects of a fully 3D atmospheric structure on exoplanet transmission spectra: retrieval biases due to day-night temperature gradients
• Mass-radius relationships for irradiated ocean planets
• Exo-Transmit: An Open-Source Code for Calculating Transmission Spectra for Exoplanet Atmospheres of Varied Composition
• Theoretical transmission spectra of exoplanet atmospheres with hydrocarbon haze: Effect of creation, growth, and settling of haze particles. I. Model description and first results
• Revised mass-radius relationships for water-rich rocky planets more irradiated than the runaway greenhouse limit
• Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations
• Strategies for Constraining the Atmospheres of Temperate Terrestrial Planets with JWST
• Microphysics of KCl and ZnS Clouds on GJ 1214b
• Strong biases in retrieved atmospheric composition caused by strong day-night chemical heterogeneities
• Transit detection of the long-period volatile-rich super-Earth ${\nu }^2$ Lupi d with $CHEOPS$
• A Criterion for the Onset of Chaos in Systems of Two Eccentric Planets
• Deflating Super-Puffs: Impact of Photochemical Hazes on the Observed Mass-Radius Relationship of Low Mass Planets
• Evidence for a lost population of close-in exoplanets
• The CARMENES search for exoplanets around M dwarfs. Two planets on the opposite sides of the radius gap transiting the nearby M dwarf LTT 3780
• A nearby transiting rocky exoplanet that is suitable for atmospheric investigation
• TRIDENT: A Rapid 3D Radiative Transfer Model for Exoplanet Transmission Spectra
• The formation of mini-Neptunes
• Updated Parameters and a New Transmission Spectrum of HD 97658b
• Information Content Analysis for Selection of Optimal JWST Observing Modes for Transiting Exoplanet Atmospheres
• A More Precise Mass for GJ 1214 b and the Frequency of Multi-Planet Systems Around Mid-M Dwarfs
• Formation and dynamics of water clouds on temperate sub-Neptunes: The example of K2-18b
• A New Model of Roche-lobe Overflow for Short-Period Gaseous Planets and Binary Stars
• Two Views of the Radius Gap and the Role of Light Curve Fitting
• Clouds in Super-Earth Atmospheres: Chemical Equilibrium Calculations
• Threshold radii of volatile-rich planets
• A Second Planet Transiting LTT 1445A and a Determination of the Masses of Both Worlds
• The TESS-Keck Survey II: An Ultra-Short Period Rocky Planet and its Siblings Transiting the Galactic Thick-Disk Star TOI-561
• Impact of the measured parameters of exoplanets on the inferred internal structure
• The JADE code: Coupling secular exoplanetary dynamics and photo-evaporation
• The importance of silicate vapor in determining the structure, radii, and envelope mass fractions of sub-Neptunes
• Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
• TOI-269 b: An eccentric sub-Neptune transiting a M2 dwarf revisited with ExTrA
• Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)
• Auto-correlation functions of astrophysical processes, and their relation to Gaussian processes; Application to radial velocities of different starspot configurations
• TOI-1231 b: A Temperate, Neptune-Sized Planet Transiting the Nearby M3 Dwarf NLTT 24399
• All along the line of sight: a closer look at opening angles and absorption regions in the atmospheres of transiting exoplanets

Cited by in corpus (13)

• Hubble Space Telescope transmission spectroscopy for the temperate sub-Neptune TOI-270d: a possible hydrogen-rich atmosphere containing water vapour
• Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy
• Water absorption in the transmission spectrum of the water-world candidate GJ9827d
• Hundreds of TESS exoplanets might be larger than we thought
• Diversity in the haziness and chemistry of temperate sub-Neptunes
• Possible Evidence for the Presence of Volatiles on the Warm Super-Earth TOI-270 b
• Super-Earth masses and stellar abundances from NIRPS reveal tentative evidence for water-rich formation around M dwarfs
• No Robust Statistical Evidence for a Population of Water Worlds in a 2025 Sample of Planets Orbiting M Stars
• On the Ordering of Exoplanet Systems
• Sub-Neptunes as Soot Factories: Deep Atmosphere Hydrocarbon Formation and Quenching as the Origin of Sub-Neptune Aerosol Trends
• NIRPS tightens the mass estimate of GJ 3090 b and detects a planet near the stellar rotation period
• Upside down: GJ3090 b the first retrograde exoplanet around an M dwarf detected with NIRPS
• Improving exoplanet mass characterisation with Bayesian model selection using the Learned Harmonic Mean Estimator