Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)

Abstract

We present the confirmation and characterisation of GJ 3473 b (G 50--16, TOI-488.01), a hot Earth-sized planet orbiting an M4 dwarf star, whose transiting signal ($P=1.1980035\pm 0.0000018\mathrm{d}$) was first detected by the Transiting Exoplanet Survey Satellite (TESS). Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, $M_b=1.86\pm 0.30{\mathrm{M}}_{\oplus },$ and radius, $R_b=1.264\pm 0.050{\mathrm{R}}_{\oplus }$. Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, $M_c\sin i=7.41\pm 0.91{\mathrm{M}}_{\oplus },$ and orbital period, $P_c=15.509\pm 0.033\mathrm{d}$. The inner planet of the system, GJ 3473 b, is one of the hottest transiting Earth-sized planets known thus far, accompanied by a dynamical mass measurement, which makes it a particularly attractive target for thermal emission spectroscopy.

arXiv comment21 pages; accepted for publication in A&A

References in corpus (122)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Galactic Stellar and Substellar Initial Mass Function
• Gaia Data Release 2. Summary of the contents and survey properties
• The Transiting Exoplanet Survey Satellite
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Gaia Data Release 2: The astrometric solution
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Las Cumbres Observatory Global Telescope Network
• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• 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
• 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
• Kepler planets: a tale of evaporation
• Most 1.6 Earth-Radius Planets are not Rocky
• 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)
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• Temperate Earth-sized planets transiting a nearby ultracool dwarf star
• The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample
• Gaia Data Release 2: Catalogue validation
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
• Growth Model Interpretation of Planet Size Distribution
• Homogeneous studies of transiting extrasolar planets. IV. Thirty systems with space-based light curves
• RadVel: The Radial Velocity Modeling Toolkit
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m Program -- Twenty New Members of the RECONS 10 Parsec Sample
• Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• C/O ratio as a Dimension for Characterizing Exoplanetary Atmospheres
• Mass-Radius Relation for Rocky Planets based on PREM
• Assessing statistical significance of periodogram peaks
• A dynamically-packed planetary system around GJ667C with three super-Earths in its habitable zone
• A seven-planet resonant chain in TRAPPIST-1
• The H$\alpha$ 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
• Juliet: a versatile modelling tool for transiting and non-transiting exoplanetary systems
• The nature of the TRAPPIST-1 exoplanets
• Kepler Data Validation I -- Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
• A stellar-mass-dependent drop in planet occurrence rates
• A new list of thorium and argon spectral lines in the visible
• Understanding The Effects Of Stellar Multiplicity On The Derived Planet Radii From Transit Surveys: Implications for Kepler, K2, and TESS
• Homogeneous studies of transiting extrasolar planets. III. Additional planets and stellar models
• Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• Transit Least Squares: Optimized transit detection algorithm to search for periodic transits of small planets
• A rocky planet transiting a nearby low-mass star
• PyTransit: Fast and Easy Exoplanet Transit Modelling in Python
• Model atmospheres of irradiated exoplanets: The influence of stellar parameters, metallicity, and the C/O ratio
• Aerosol Composition of Hot Giant Exoplanets Dominated by Silicates and Hydrocarbon Hazes
• Near-infrared Metallicities, Radial Velocities and Spectral Types for 447 Nearby M Dwarfs
• The CARMENES search for exoplanets around M dwarfs: Different roads to radii and masses of the target stars
• They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• A public HARPS radial velocity database corrected for systematic errors
• Transit Detection in the MEarth Survey of Nearby M Dwarfs: Bridging the Clean-First, Search-Later Divide
• Kepler Planet Occurrence Rates for Mid-Type M Dwarfs as a Function of Spectral Type
• Evolution of the radius valley around low mass stars from $Kepler$ and $K2$
• CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions
• 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
• The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems
• BGLS: A Bayesian formalism for the generalised Lomb-Scargle periodogram
• CARMENES input catalogue of M dwarfs: III. Rotation and activity from high-resolution spectroscopic observations
• The L 98-59 System: Three Transiting, Terrestrial-Sized Planets Orbiting a Nearby M-dwarf
• A giant exoplanet orbiting a very low-mass star challenges planet formation models
• Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
• The MACHO Project LMC Variable Star Inventory. IX. Frequency Analysis of the First Overtone RR Lyrae Stars and the Indication for Nonradial Pulsations
• Correcting HIRES radial velocities for small systematic errors
• Planets Formed in Habitable Zones of M Dwarf Stars Probably are Deficient in Volatiles
• The CARMENES search for exoplanets around M dwarfs. Activity indicators at visible and near-infrared wavelengths
• The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopy
• Early 2017 observations of TRAPPIST-1 with $\text{Spitzer}$
• A second terrestrial planet orbiting the nearby M dwarf LHS 1140
• Transiting exoplanet candidates from K2 Campaigns 5 and 6
• Stacked Bayesian general Lomb-Scargle periodogram: Identifying stellar activity signals
• Measurements of Transit Timing Variations for WASP-5b
• A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780
• Strategies for Constraining the Atmospheres of Temperate Terrestrial Planets with JWST
• The New Generation Planetary Population Synthesis (NGPPS). III. Warm super-Earths and cold Jupiters: A weak occurrence correlation, but with a strong architecture-composition link
• The CARMENES search for exoplanets around M dwarfs -- Photospheric parameters of target stars from high-resolution spectroscopy. II. Simultaneous multiwavelength range modeling of activity insensitive lines
• Rocky super-Earths or waterworlds: the interplay of planet migration, pebble accretion and disc evolution
• The CARMENES search for exoplanets around M dwarfs. Radial velocities and activity indicators from cross-correlation functions with weighted binary masks
• Multicolour photometry for exoplanet candidate validation
• MuSCAT: a multicolor simultaneous camera for studying atmospheres of transiting exoplanets
• The Hunt for Exomoons with Kepler (HEK): IV. A Search for Moons around Eight M-Dwarfs
• The Planetary Mass-Radius Relation and its Dependence on Orbital Period as Measured by Transit Timing Variations and Radial Velocities
• 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
• Characterization of the L 98-59 multi-planetary system with HARPS: two confirmed terrestrial planets and a mass upper limit on the third
• Radial velocity follow-up of GJ1132 with HARPS. A precise mass for planet 'b' and the discovery of a second planet
• Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres
• HD 1397b: a transiting warm giant planet orbiting a V = 7.8 mag sub-giant star discovered by TESS
• The CARMENES search for exoplanets around M dwarfs - HD 147379b: A nearby Neptune in the temperate zone of an early-M dwarf
• Agatha: disentangling periodic signals from correlated noise in a periodogram framework
• A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS
• From cold to hot irradiated gaseous exoplanets: Fingerprints of chemical disequilibrium in atmospheric spectra
• The CARMENES search for exoplanets around M dwarfs. Measuring precise radial velocities in the near infrared: the example of the super-Earth CD Cet b
• Evidence for Spin-orbit Alignment in the TRAPPIST-1 System
• Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?
• GJ 1252 b: A 1.2 $R_{\oplus }$ planet transiting an M3-dwarf at 20.4 pc
• TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
• From cold to hot irradiated gaseous exoplanets: Toward an observation-based classification scheme
• A multiple planet system of super-Earths orbiting the brightest red dwarf star GJ887
• Absolute densities in exoplanetary systems: photodynamical modelling of Kepler-138
• The role of clouds on the depletion of methane and water dominance in the transmission spectra of irradiated exoplanets
• TOI-150b and TOI-163b: two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZ
• The Gold Standard: Accurate Stellar and Planetary Parameters for Eight Kepler M dwarf Systems Enabled by Parallaxes
• GJ357: A low-mass planetary system uncovered by precision radial-velocities and dynamical simulations
• HATS-54b-HATS-58Ab: five new transiting hot Jupiters including one with a possible temperate companion
• HADES RV program with HARPS-N at TNG. IX. A super-Earth around the M dwarf Gl686
• Exoplanet Radius Gap Dependence on Host Star Type
• The CARMENES search for exoplanets around M dwarfs Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital parameters of a super-Earth around GJ 686 (BD+18 3421)
• The HADES RV Programme with HARPS-N at TNG XI. GJ 685 b: a warm super-Earth around an active M dwarf

Cited by in corpus (26)

• The CARMENES search for exoplanets around M dwarfs -- Planet occurrence rates from a subsample of 71 stars
• The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)
• RV-detected planets around M dwarfs: Challenges for core accretion models
• A More Precise Mass for GJ 1214 b and the Frequency of Multi-Planet Systems Around Mid-M Dwarfs
• A Second Planet Transiting LTT 1445A and a Determination of the Masses of Both Worlds
• An ultra-short-period transiting super-Earth orbiting the M3 dwarf TOI-1685
• Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)
• The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc
• The TIME Table: Rotation and Ages of Cool Exoplanet Host Stars
• The CARMENES search for exoplanets around M dwarfs, Wolf 1069 b: Earth-mass planet in the habitable zone of a nearby, very low-mass star
• Discovery and mass measurement of the hot, transiting, Earth-sized planet GJ 3929 b
• GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot, low-density super-Earth
• GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation
• The LHS 1678 System: Two Earth-Sized Transiting Planets and an Astrometric Companion Orbiting an M Dwarf Near the Convective Boundary at 20 pc
• The Atmospheres of Rocky Exoplanets II. Influence of surface composition on the diversity of cloud condensates
• TOI-1801 b: A temperate mini-Neptune around a young M0.5 dwarf
• A multi-planetary system orbiting the early-M dwarf TOI-1238
• Detection capability of ground-based meter-sized telescopes for shallow exoplanet transits
• Two sub-Neptunes around the M dwarf TOI-1470
• Null transit detections of 68 radial velocity exoplanets observed by TESS
• No Robust Statistical Evidence for a Population of Water Worlds in a 2025 Sample of Planets Orbiting M Stars
• Hot Rocks Survey V: Secondary Eclipse Photometry of GJ 3473 b with JWST/MIRI
• TOI-1634 b: an Ultra-Short Period Keystone Planet Sitting Inside the M Dwarf Radius Valley
• TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf
• Improved characterization of the TOI-2141 system: a dense sub-Neptune with non-transiting inner and outer companions
• GJ 3929 b as the First Complete Rocky Worlds DDT Data Set