A possibly inflated planet around the bright, young star DS Tuc A

Abstract

The origin of the observed diversity of planetary system architectures is one of the main topic of the exoplanetary research. The detection of a statistically significant sample of planets around young stars allows us to study the early stages of planet formation and evolution, but only a handful of them is known so far. In this regard, a considerable contribution is expected from the NASA TESS satellite, which is now performing a survey of $\sim 85\%$ of the sky to search for short-period transiting planets In its first month of operations, TESS found a planet candidate with an orbital period of 8.14 days around a member of the Tuc-Hor young association ($\sim$ 40 Myr), the G6V main component of the binary system DS\,Tuc. If confirmed, it would be the first transiting planet around a young star suitable for radial velocity and/or atmospheric characterization. We aim to validate the planetary nature of this companion and to measure its orbital and physical parameters. We obtain accurate planet parameters by coupling an independent reprocessing of the TESS light curve with improved stellar parameters and the dilution caused by the binary companion; we analyse high precision archival radial velocities to impose an upper limit of about 0.1 M${}_{\mathrm{Jup}}$ on the planet mass; we finally rule out the presence of external companions beyond 40 au with adaptive optics images. We confirm the presence of a young, giant ($\mathrm{R}=0.50$ R${}_{\mathrm{Jup}}$) planet having a not negligible possibility to be inflated (theoretical mass $\lesssim 20$ M${}_{\oplus }$) around DS\,Tuc~A. We discuss the feasibility of mass determination, Rossiter-McLaughlin analysis and atmosphere characterization, allowed by the brightness of the star.

arXiv comment12 pages, 11 figures. Accepted for publication in A&A

References in corpus (66)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Transiting Exoplanet Survey Satellite
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• batman: BAsic Transit Model cAlculatioN in Python
• Dynamical Outcomes of Planet-Planet Scattering
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• EXOFAST: A fast exoplanetary fitting suite in IDL
• The TESS Input Catalog and Candidate Target List
• The CORALIE survey for southern extra-solar planets VII. Two short-period Saturnian companions to HD108147 and HD168746
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood
• PolyChord: next-generation nested sampling
• Basic physical parameters of a selected sample of evolved stars
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• The HARPS-TERRA project I. Description of the algorithms, performance and new measurements on a few remarkable stars observed by HARPS
• Evolution of low-mass star and brown dwarf eclipsing binaries
• 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
• On the Correlation between the Magnetic Activity Levels, the Metallicities and the Radii of Low-Mass Stars
• The Tucana/Horologium, Columba, AB Doradus, and Argus Associations: New Members and Dusty Debris Disks
• An Efficient Automated Validation Procedure for Exoplanet Transit Candidates
• Transit Least Squares: Optimized transit detection algorithm to search for periodic transits of small planets
• Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices
• 197 Candidates and 104 Validated Planets in K2's First Five Fields
• Hot Jupiters from Coplanar High-eccentricity Migration
• A Stellar Census of the Tucana-Horologium Moving Group
• Stellar and Planetary Properties of K2 Campaign 1 Candidates and Validation of 17 Planets, Including a Planet Receiving Earth-like Insolation
• 275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0-10
• A rotational and variability study of a large sample of PMS stars in NGC 2264
• TESS Hunt for Young and Maturing Exoplanets (THYME): A planet in the 45 Myr Tucana-Horologium association
• Identification of a nearby stellar association in the Hipparcos catalog: implications for recent, local star formation
• Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
• A hot Jupiter orbiting a 2-Myr-old solar-mass T Tauri star
• A novel L-band imaging search for giant planets in the Tucana and Beta Pictoris moving groups
• RACE-OC Project: Rotation and variability in young stellar associations within 100 pc
• An ultra-short period rocky super-Earth with a secondary eclipse and a Neptune-like companion around K2-141
• The GAPS programme with HARPS-N at TNG XI. Pr~0211 in M~44: the first multi-planet system in an open cluster
• A new method to compute limb-darkening coefficients for stellar atmosphere models with spherical symmetry: the space missions TESS, Kepler, Corot, and MOST
• The MACHO Project LMC Variable Star Inventory. IX. Frequency Analysis of the First Overtone RR Lyrae Stars and the Indication for Nonradial Pulsations
• Kepler-21b: A rocky planet around a V = 8.25 magnitude star
• The VLT/NaCo Large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits: I- Sample definition and characterization
• Two Empirical Regimes of the Planetary Mass-Radius Relation
• Search for associations containing young stars (SACY):II. Chemical abundances of stars in 11 young Associations in the Solar neighborhood
• Chemical composition of the young open clusters IC2602 and IC2391
• Comparison of the power-2 limb-darkening law from the Stagger-grid to Kepler light curves of transiting exoplanets
• A PSF-based approach to Kepler/K2 data. I. Variability within the K2 Campaign 0 star clusters M 35 and NGC 2158
• A giant planet in the triple system HD132563
• The HADES RV Programme with HARPS-N@TNG II. Data treatment and simulations
• A critical reassessment of the fundamental properties of GJ 504: Chemical composition and age
• Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
• Variable stars in two open clusters within the Kepler 2-Campaign-0 field: M 35 and NGC 2158
• Solar twins and the Barium puzzle
• Multi-band high resolution spectroscopy rules out the hot Jupiter BD+20 1790b - First data from the GIARPS Commissioning
• A PSF-based approach to Kepler/K2 data - III. Search for exoplanets and variable stars within the open cluster M 67 (NGC 2682)
• Three-dimensional simulations of near-surface convection in main-sequence stars. IV. Effect of small-scale magnetic flux concentrations on centre-to-limb variation and spectral lines
• A vigorous activity cycle mimicking a planetary system in HD200466
• Fe I and Fe II Abundances of Solar-Type Dwarfs in the Pleiades Open Cluster
• The GAPS Programme with HARPS-N at TNG XVII. Line profile indicators and kernel regression as diagnostics of radial-velocity variations due to stellar activity in solar-like stars
• A search for planets in the metal-enriched binary HD 219542
• A direct imaging search for close stellar and sub-stellar companions to young nearby stars
• Validation of a Temperate Fourth Planet in the K2-133 Multi-planet System

Cited by in corpus (43)

• Four newborn planets transiting the young solar analog V1298 Tau
• Flare Statistics for Young Stars from a Convolutional Neural Network Analysis of $\text{TESS}$ Data
• TESS Hunt for Young and Maturing Exoplanets (THYME) III: a two-planet system in the 400 Myr Ursa Major Group
• Deflating Super-Puffs: Impact of Photochemical Hazes on the Observed Mass-Radius Relationship of Low Mass Planets
• TESS Hunt for Young and Maturing Exoplanets (THYME) VI: an 11 Myr giant planet transiting a very low-mass star in Lower Centaurus Crux
• The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47 Tuc
• TESS Hunt for Young and Maturing Exoplanets (THYME) V: A Sub-Neptune Transiting a Young Star in a Newly Discovered 250 Myr Association
• The GAPS Programme at TNG XXI -- A GIARPS case-study of known young planetary candidates: confirmation of HD 285507 b and refutation of AD Leo b
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- II. Search for exoplanets in open clusters of the southern ecliptic hemisphere and their frequency
• Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets
• Constraints on the mass and atmospheric composition and evolution of the low-density young planet DS Tuc A b
• TESS Observations of the Luhman 16AB Brown Dwarf System: Rotational Periods, Lightcurve Evolution, and Zonal Circulation
• The GAPS Programme with HARPS-N at TNG. XXXVII. A precise density measurement of the young ultra-short period planet TOI-1807 b
• Constraining the entropy of formation from young transiting planets
• Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076
• AU Microscopii in the FUV: Observations in Quiescence, During Flares, and Implications for AU Mic b and c
• H-alpha and Ca II Infrared Triplet Variations During a Transit of the 23 Myr Planet V1298 Tau c
• The GAPS Programme at TNG XXVIII -- A pair of hot-Neptunes orbiting the young star TOI-942
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- III. Exploring the properties of young associations through their variables, dippers, and candidate exoplanets
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- IV. Candidate exoplanets around stars in open clusters: frequency and age-planetary radius distribution
• V1298 Tau with TESS: Updated Ephemerides, Radii, and Period Constraints from a Second Transit of V1298 Tau e
• A Mini-Neptune from TESS and CHEOPS Around the 120 Myr Old AB Dor member HIP 94235
• The Young Planet DS Tuc Ab has a Low Obliquity
• A 38 Million Year Old Neptune-Sized Planet in the Kepler Field
• The three regimes of atmospheric evaporation for super-Earths and sub-Neptunes
• The GAPS program at TNG XLVII: The unusual formation history of V1298 Tau
• TOI-179: a young system with a transiting compact Neptune-mass planet and a low-mass companion in outer orbit
• X-ray flares of the young planet host DS Tuc A
• Rotation periods of TESS Objects of Interest from the Magellan-TESS Survey with multiband photometry from Evryscope and TESS
• NEID Reveals that The Young Warm Neptune TOI-2076 b Has a Low Obliquity
• Multiplicity of stars with planets in the solar neighbourhood
• Updated Planetary Mass Constraints of the Young V1298 Tau System Using MAROON-X
• YOUNG Star detrending for Transiting Exoplanet Recovery (YOUNGSTER) -- I. A search for young exoplanets in Sectors 1-5 of the TESS Full-Frame-Images
• TOI-837 b: characterisation, formation and evolutionary history of an infant warm Saturn-mass planet
• XUV irradiation of young planetary atmospheres. Results from a joint XMM-Newton and HST observation of HIP67522
• TIC~257060897b: an inflated, low-density, hot-Jupiter transiting a rapidly evolving subgiant star
• The GAPS programme at TNG XLIII. A massive brown dwarf orbiting the active M dwarf TOI-5375
• The GAPS Programme at TNG. LXV. Precise density measurement of TOI-1430 b, a young planet with an evaporating atmosphere
• Discovering planets with PLATO: Comparison of algorithms for stellar activity filtering
• Nearby Young Stars and Young Moving Groups
• AU Mic b is the Youngest Planet to have a Spin-Orbit Alignment Measurement
• The GAPS Programme at the TNG: LXX. TOI-5734b: A hot sub-Neptune orbiting a relatively young K dwarf with an Earth-like density