TESS discovery of a super-Earth and two sub-Neptunes orbiting the bright, nearby, Sun-like star HD 22946

Abstract

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of a three-planet system around the bright Sun-like star HD~22946(V=8.3 mag),also known as TIC~100990000, located 63 parsecs away.The system was observed by TESS in Sectors 3, 4, 30 and 31 and two planet candidates, labelled TESS Objects of Interest (TOIs) 411.01 (planet $c$) and 411.02 (planet $b$), were identified on orbits of 9.57 and 4.04 days, respectively. In this work, we validate the two planets and recover an additional single transit-like signal in the light curve, which suggests the presence of a third transiting planet with a longer period of about 46 days.We assess the veracity of the TESS transit signals and use follow-up imaging and time series photometry to rule out false positive scenarios, including unresolved binary systems, nearby eclipsing binaries or background/foreground stars contaminating the light curves. Parallax measurements from Gaia EDR3, together with broad-band photometry and spectroscopic follow-up by TFOP allowed us to constrain the stellar parameters of TOI-411, including its radius of$1.157\pm 0.025R_{\odot }$. Adopting this value, we determined the radii for the three exoplanet candidates and found that planet $b$ is a super-Earth, with a radius of $1.72\pm 0.10R_{\oplus }$, while planet $c$ and $d$ are sub-Neptunian planets, with radii of$2.74\pm 0.14R_{\oplus }$ and $3.23\pm 0.19R_{\oplus }$ respectively. By using dynamical simulations, we assessed the stability of the system and evaluated the possibility of the presence of other undetected, non-transiting planets by investigating its dynamical packing. We find that the system is dynamically stable and potentially unpacked, with enough space to host at least one more planet between $c$ and $d$.(Abridged)

arXiv comment21 pages, 12 figures. Accepted for publication on A&A

References in corpus (74)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• 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
• Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• 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
• Accurate masses and radii of normal stars: modern results and applications
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Understanding the Lomb-Scargle Periodogram
• Las Cumbres Observatory Global Telescope Network
• The false positive rate of Kepler and the occurrence of planets
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• A box-fitting algorithm in the search for periodic transits
• 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
• Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
• The evaporation valley in the Kepler planets
• Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates
• 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
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• 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
• Validation of Kepler's Multiple Planet Candidates. III: Light Curve Analysis & Announcement of Hundreds of New Multi-planet Systems
• Core-powered mass loss and the radius distribution of small exoplanets
• The angular size of dwarf stars and subgiants - Surface brightness relations calibrated by interferometry
• Stellar and substellar companions of nearby stars from Gaia DR2 - Binarity from proper motion anomaly
• STARRY: Analytic Occultation Light Curves
• Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
• 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
• Understanding The Effects Of Stellar Multiplicity On The Derived Planet Radii From Transit Surveys: Implications for Kepler, K2, and TESS
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• A Super-Earth Transiting a Naked-Eye Star
• Planetary nebulae seen with TESS: Discovery of new binary central star candidates from Cycle 1
• Stellar and substellar companions from Gaia EDR3 -- Proper motion anomaly and resolved common proper motion pairs
• The Kepler Follow-Up Observation Program. I. A Catalog of Companions to Kepler Stars from High-Resolution Imaging
• CHEOPS: A Transit Photometry Mission for ESA's Small Mission Programme
• 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
• SOAR TESS Survey. I: Sculpting of TESS planetary systems by stellar companions
• Validation of Kepler's Multiple Planet Candidates. II: Refined Statistical Framework and Descriptions of Systems of Special Interest
• exoplanet: Gradient-based probabilistic inference for exoplanet data & other astronomical time series
• Eclipsing Binary Stars as Benchmarks for Trigonometric Parallaxes in the Gaia Era
• Ten years of speckle interferometry at SOAR
• Photometric detection of non-transiting short-period low-mass companions through the beaming, ellipsoidal and reflection effects in Kepler and CoRoT lightcurves
• HD 80606 b, a planet on an extremely elongated orbit
• A First Comparison of Kepler Planet Candidates in Single and Multiple Systems
• Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates
• Warm terrestrial planet with half the mass of Venus transiting a nearby star
• A rich population of free-floating planets in the Upper Scorpius young stellar association
• Construction of a Calibrated Probabilistic Classification Catalog: Application to 50k Variable Sources in the All-Sky Automated Survey
• Superabundance of Exoplanet Sub-Neptunes Explained by Fugacity Crisis
• The astrophysics of visible-light orbital phase curves in the space age
• The Solar Neighborhood XLIX: Nine Giant Planets Orbiting Nearby K Dwarfs, and the CHIRON Spectrograph's Radial Velocity Performance
• Switchbacks: statistical properties and deviations from alfvénicity
• Detection of an Atmosphere on a Rocky Exoplanet
• The ASAS-SN Catalog of Variable Stars IX: The Spectroscopic Properties of Galactic Variable Stars
• Speckle Imaging Excludes Low-Mass Companions Orbiting the Exoplanet Host Star TRAPPIST-1
• Discovery and Vetting of Exoplanets I: Benchmarking K2 Vetting Tools
• SOAR TESS Survey. II: The impact of stellar companions on planetary populations
• No escaping helium from 55 Cnc e
• Astrophysical Insights into Radial Velocity Jitter from an Analysis of 600 Planet-search Stars
• Current Population Statistics Do Not Favor Photoevaporation over Core-Powered Mass Loss as the Dominant Cause of the Exoplanet Radius Gap
• Planet Hunters TESS II: Findings from the first two years of TESS
• Orbital Dynamics of Multi-Planet Systems with Eccentricity Diversity
• TESS Delivers Five New Hot Giant Planets Orbiting Bright Stars from the Full Frame Images
• Stellar activity as a tracer of moving groups
• Inner rocky super-Earth formation: distinguishing the formation pathways in viscously heated and passive discs
• The TESS Triple-9 Catalog: 999 uniformly vetted candidate exoplanets
• Resolving Close Encounters: Stability in the HD 5319 and HD 7924 Planetary Systems

Cited by in corpus (1)

• Refined parameters of the HD 22946 planetary system and the true orbital period of planet d