Planet Hunters TESS V: a planetary system around a binary star, including a mini-Neptune in the habitable zone

Abstract

We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright (V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 RSun, M = 1.10 MSun). The planet was identified in data from the Transiting Exoplanet Survey Satellite by citizen scientists taking part in the Planet Hunters TESS project. Modeling of the transit events yields an orbital period of 271.9445 +/- 0.0040 days and radius of 3.2 +/- 0.20 REarth. The Earth-like orbital period and an incident flux of 1.56 +/- 0.2 places it in the optimistic habitable zone around the star. Doppler spectroscopy of the system allowed us to place an upper mass limit on the transiting planet and revealed a non-transiting planet candidate in the system with a period of 34.15 +/- 0.15 days. Furthermore, the combination of archival data dating back to 1905 with new high angular resolution imaging revealed a stellar companion orbiting the primary star with an orbital period of around 230 years and an eccentricity of about 0.9. The long period of the transiting planet, combined with the high eccentricity and close approach of the companion star makes this a valuable system for testing the formation and stability of planets in binary systems.

24 pages, 16 figures, 4 tables

References in corpus (96)

• Scikit-learn: Machine Learning in Python
• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The Transiting Exoplanet Survey Satellite
• Analytic Lightcurves for Planetary Transit Searches
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Galaxy Zoo : Morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey
• Accurate masses and radii of normal stars: modern results and applications
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• batman: BAsic Transit Model cAlculatioN in Python
• Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
• The Revised TESS Input Catalog and Candidate Target List
• A box-fitting algorithm in the search for periodic transits
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• The Eccentric Kozai-Lidov Effect and Its Applications
• The CoRoT satellite in flight : description and performance
• astroquery: An Astronomical Web-Querying Package in Python
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• No planet for HD 166435
• Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code
• RadVel: The Radial Velocity Modeling Toolkit
• Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
• The California Planet Survey I. Four New Giant Exoplanets
• The TESS Objects of Interest Catalog from the TESS Prime Mission
• Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology
• Kepler Data Validation I -- Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
• Dynamic temperature selection for parallel-tempering in Markov chain Monte Carlo simulations
• Limb and gravity-darkening coefficients for the TESS satellite at several metallicities, surface gravities, and microturbulent velocities
• Precision Stellar Characterization of FGKM Stars using an Empirical Spectral Library
• On the Formation of Hot Jupiters in Stellar Binaries
• The Role of Multiplicity in Disk Evolution and Planet Formation
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• Hints for a Turnover at the Snow Line in the Giant Planet Occurrence Rate
• The Kepler Follow-Up Observation Program. I. A Catalog of Companions to Kepler Stars from High-Resolution Imaging
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• WASP-3b: a strongly-irradiated transiting gas-giant planet
• Revisited Mass-Radius relations for exoplanets below 120 Earth masses
• Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices
• Misaligned spin-orbit in the XO-3 planetary system?
• Eclipsing Binary Stars as Benchmarks for Trigonometric Parallaxes in the Gaia Era
• A new library of theoretical stellar spectra with scaled-solar and alpha-enhanced mixtures
• Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets
• Empirical, Accurate Masses and Radii of Single Stars with TESS and Gaia
• Fluxes in Hαand Ca II H and K for a sample of Southern stars
• Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates
• orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community
• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• Terrestrial Planet Formation Around Individual Stars Within Binary Star Systems
• SOPHIE+: First results of an octagonal-section fiber for high-precision radial velocity measurements
• Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
• Impact of Binary Stars on Planet Statistics -- I. Planet Occurrence Rates, Trends with Stellar Mass, and Wide Companions to Hot Jupiter Hosts
• The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles
• Hot Jupiters are Destroyed by Tides While Their Host Stars are on the Main Sequence
• Observational constraints on dust disk sizes in tidally truncated protoplanetary disks in multiple systems in the Taurus region
• The First Habitable Zone Earth-sized Planet from TESS. I: Validation of the TOI-700 System
• Pyaneti: a fast and powerful software suite for multi-planet radial velocity and transit fitting
• pyaneti II: A multidimensional Gaussian process approach to analysing spectroscopic time-series
• Evidence against the young hot-Jupiter around BD +20 1790
• Kronos & Krios: Evidence for accretion of a massive, rocky planetary system in a comoving pair of solar-type stars
• Practical Planet Prospecting
• Detection of Stars within $\sim$0.8 arcseconds of Kepler Objects of Interest
• Stellar clustering shapes the architectures of planetary systems
• Do stellar magnetic cycles influence the measurement of precise radial velocities?
• New prospects for observing and cataloguing exoplanets in well detached binaries
• The Curious Case of Elemental Abundance Differences in the Dual Hot Jupiter Hosts WASP-94AB
• One year of AU Mic with HARPS: II -- stellar activity and star-planet interaction
• Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
• SOAR TESS Survey. II: The impact of stellar companions on planetary populations
• Influence of Stellar Multiplicity On Planet Formation. IV. Adaptive Optics Imaging of Kepler Stars With Multiple Transiting Planet Candidates
• Orbital Stability of Circumstellar Planets in Binary Systems
• The young HD 73583 (TOI-560) planetary system: Two 10-M${}_{\oplus }$ mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf
• Planet Hunters TESS II: Findings from the first two years of TESS
• Orbital Architectures of Planet-Hosting Binaries II. Low Mutual Inclinations Between Planetary and Stellar Orbits
• The First Habitable Zone Earth-Sized Planet From TESS II: $Spitzer$ Confirms TOI-700 d
• The Magellan PFS Planet Search Program: Radial Velocity and Stellar Abundance Analyses of the 360 AU, Metal-Poor Binary "Twins" HD 133131A & B
• Hidden Planetary Friends: On the Stability Of 2-Planet Systems in the Presence of a Distant, Inclined Companion
• Stellar Companions to TESS Objects of Interest: A Test of Planet-Companion Alignment
• A Possible Alignment Between the Orbits of Planetary Systems and their Visual Binary Companions
• Robo-AO Kepler Survey V: The effect of physically associated stellar companions on planetary systems
• The TESS-Keck Survey. VIII. Confirmation of a Transiting Giant Planet on an Eccentric 261 day Orbit with the Automated Planet Finder Telescope
• High-Eccentricity Migration with Disk-Induced Spin-Orbit Misalignment: a Preference for Perpendicular Hot Jupiters
• A Second Earth-Sized Planet in the Habitable Zone of the M Dwarf, TOI-700
• A 1.55 R${}_{\oplus }$ habitable-zone planet hosted by TOI-715, an M4 star near the ecliptic South Pole
• The Stellar Obliquity and the Long-period planet in the HAT-P-17 Exoplanetary System
• Planet Engulfment Signatures in Twin Stars
• Ploonets: formation, evolution and detectability of tidally detached exomoons
• Detecting Unresolved Binaries in TESS Data with Speckle Imaging
• Stellar multiplicity affects the correlation between proto-planetary disc masses and accretion rates: binaries explain high-accretors in Upper Sco
• Relativistic Dynamical Stability Criterion of Multi-Planet Systems with a Distant Companion
• TOI-4562 b: A highly eccentric temperate Jupiter analog orbiting a young field star
• Hiding Planets Near and Far: The Parameter Space of Hidden Companions for Known Planetary Systems

Cited by in corpus (2)

• Hundreds of TESS exoplanets might be larger than we thought
• Validating the Orbital Periods of the Coolest TESS Exoplanet Candidates