TESS Hunt for Young and Maturing Exoplanets (THYME) VII : Membership, rotation, and lithium in the young cluster Group-X and a new young exoplanet

Abstract

The public, all-sky surveys Gaia and TESS provide the ability to identify new young associations and determine their ages. These associations enable study of planetary evolution by providing new opportunities to discover young exoplanets. A young association was recently identified by Tang et al. and F{ü}rnkranz et al. using astrometry from Gaia (called "Group-X" by the former). In this work, we investigate the age and membership of this association; and we validate the exoplanet TOI 2048 b, which was identified to transit a young, late G dwarf in Group-X using photometry from TESS. We first identified new candidate members of Group-X using Gaia EDR3 data. To infer the age of the association, we measured rotation periods for candidate members using TESS data. The clear color--period sequence indicates that the association is the same age as the $300\pm 50$ Myr-old NGC 3532. We obtained optical spectra for candidate members that show lithium absorption consistent with this young age. Further, we serendipitously identify a new, small association nearby Group-X, which we call MELANGE-2. Lastly, we statistically validate TOI 2048 b, which is $2.6\pm 0.2$ \rearth\ radius planet on a 13.8-day orbit around its 300 Myr-old host star.

arXiv commentRevised to correct error in reported planet radius (original: 2.1 Earth radii, corrected: 2.6 Earth radii) and units for planetary radius ratio entries in Table 8. All data tables available open-access with the AJ article

References in corpus (112)

• 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 Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Gaia mission
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• Gaia Data Release 2: The astrometric solution
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The Dartmouth Stellar Evolution Database
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• Las Cumbres Observatory Global Telescope Network
• Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• astroquery: An Astronomical Web-Querying Package in Python
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• Gaia Early Data Release 3: Photometric content and validation
• The evaporation valley in the Kepler planets
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• The TESS Input Catalog and Candidate Target List
• 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
• On the rotational evolution of solar- and late-type stars, its magnetic origins, and the possibility of stellar gyrochronology
• PARSEC evolutionary tracks of massive stars up to $350M_{\odot }$ at metallicities 0.0001$\le Z\le$0.04
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
• The Ages of Stars
• Asteroseismology of Solar-Type and Red-Giant Stars
• Core-powered mass loss and the radius distribution of small exoplanets
• The Thirteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey MApping Nearby Galaxies at Apache Point Observatory
• The TESS Objects of Interest Catalog from the TESS Prime Mission
• Unresolved stellar companions with Gaia DR2 astrometry
• HAT-P-16b: A 4 Mj Planet Transiting A Bright Star On An Eccentric Orbit
• Parametrizing the exoplanet eccentricity distribution with the Beta distribution
• The Impact of Stellar Multiplicity on Planetary Systems, I.: The Ruinous Influence of Close Binary Companions
• Determining stellar macroturbulence using asteroseismic rotational velocities from Kepler
• Real-time processing of the imaging data from the network of Las Cumbres Observatory Telescopes using BANZAI
• A planet within the debris disk around the pre-main-sequence star AU Microscopii
• Planetary Candidates from the First Year of the K2 Mission
• Rotation in the Pleiades with K2: I. Data and First Results
• exoplanet: Gradient-based probabilistic inference for exoplanet data & other astronomical time series
• Untangling the Galaxy I: Local Structure and Star Formation History of the Milky Way
• Barycentric Corrections at 1 cm/s for precise Doppler velocities
• PALM-3000: Exoplanet Adaptive Optics for the 5-meter Hale Telescope
• Zodiacal Exoplanets in Time (ZEIT) III: A short-period planet orbiting a pre-main-sequence star in the Upper Scorpius OB Association
• When Do Stalled Stars Resume Spinning Down? Advancing Gyrochronology with Ruprecht 147
• TESS Hunt for Young and Maturing Exoplanets (THYME): A planet in the 45 Myr Tucana-Horologium association
• Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates
• K2 rotation periods for low-mass Hyads and a quantitative comparison of the distribution of slow rotators in the Hyades and Praesepe
• Comoving stars in Gaia DR1: An abundance of very wide separation co-moving pairs
• The Hyades tidal tails revealed by Gaia DR2
• Four newborn planets transiting the young solar analog V1298 Tau
• Zodiacal Exoplanets in Time (ZEIT) IV: seven transiting planets in the Praesepe cluster
• Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars
• YBC, a stellar bolometric corrections database with variable extinction coefficients: an application to PARSEC isochrones
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• TESS Spots a Compact System of Super-Earths around the Naked-Eye Star HR 858
• Python Leap Second Management and Implementation of Precise Barycentric Correction (barycorrpy)
• WIYN Open Cluster Study. LXXV. Testing the Metallicity Dependence of Stellar Lithium Depletion Using Hyades-Aged Clusters. 1. Hyades & Praesepe
• Extended stellar systems in the solar neighborhood -- V. Discovery of coronae of nearby star clusters
• Very regular high-frequency pulsation modes in young intermediate-mass stars
• Extended stellar systems in the solar neighborhood - I. The tidal tails of the Hyades
• TESS Hunt for Young and Maturing Exoplanets (THYME) II: A 17 Myr Old Transiting Hot Jupiter in the Sco-Cen Association
• New Grids of Pure-Hydrogen White-Dwarf NLTE Model Atmospheres \newline and the HST/STIS Flux Calibration
• Measuring the Recoverability of Close Binaries in Gaia DR2 with the Robo-AO Kepler Survey
• Extended stellar systems in the solar neighborhood - II. Discovery of a nearby 120° stellar stream in Gaia DR2
• TESS Hunt for Young and Maturing Exoplanets (THYME) III: a two-planet system in the 400 Myr Ursa Major Group
• The lithium-rotation connection in the 125 Myr-old Pleiades cluster
• Discovery of Tidal Tails in Disrupting Open Clusters: Coma Berenices and a Neighbor Stellar Group
• A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence Rates
• Multicolour photometry for exoplanet candidate validation
• Zodiacal Exoplanets in Time (ZEIT) VI: a three-planet system in the Hyades cluster including an Earth-sized planet
• Revised Filter Profiles and Zero Points for Broadband Photometry
• A New Look at an Old Cluster: The Membership, Rotation, and Magnetic Activity of Low-Mass Stars in the 1.3-Gyr-Old Open Cluster NGC 752
• A warm Jupiter-sized planet transiting the pre-main sequence star V1298 Tau
• Zodiacal Exoplanets in Time (ZEIT) VIII: A Two Planet System in Praesepe from K2 Campaign 16
• TESS Hunt for Young and Maturing Exoplanets (THYME) VI: an 11 Myr giant planet transiting a very low-mass star in Lower Centaurus Crux
• MuSCAT2: four-color Simultaneous Camera for the 1.52-m Telescopio Carlos Sánchez
• K2 Discovers a Busy Bee: An Unusual Transiting Neptune Found in the Beehive Cluster
• The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
• Radial velocity confirmation of K2-100b: a young, highly irradiated, and low density transiting hot Neptune
• TESS Hunt for Young and Maturing Exoplanets (THYME) V: A Sub-Neptune Transiting a Young Star in a Newly Discovered 250 Myr Association
• StarGO: A New Method to Identify the Galactic Origins of Halo Stars
• Flares, Rotation, and Planets of the AU Mic System from TESS Observations
• New Pleiades Eclipsing Binaries and a Hyades Transiting System Identified by K2
• TESS Hunt for Young and Maturing Exoplanets (THYME) IV: Three small planets orbiting a 120 Myr-old star in the Pisces--Eridanus stream
• Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602
• A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus
• Characterizing Undetected Stellar Companions with Combined Datasets
• Transmission spectroscopy and Rossiter-McLaughlin measurements of the young Neptune orbiting AU Mic
• First eROSITA study of nearby M dwarfs and the rotation-activity relation in combination with TESS
• BAFFLES: Bayesian Ages for Field Lower-Mass Stars
• Constraints on the mass and atmospheric composition and evolution of the low-density young planet DS Tuc A b
• Contrast sensitivities in the Gaia Data Release 2
• A Closer Look at Exoplanet Occurrence Rates: Considering the Multiplicity of Stars Without Detected Planets
• New and Known Moving Groups And Clusters Identified in a Gaia Co-Moving Catalog
• ShaneAO: wide science spectrum adaptive optics system for the Lick Observatory
• Extended stellar systems in the solar neighborhood - III. Like ships in the night: the Coma Berenices neighbor moving group
• Rotation periods for cool stars in the open cluster NGC 3532. The transition from fast to slow rotation
• Three K2 Campaigns Yield Rotation Periods for 1013 Stars in Praesepe
• Deep, Wide-field CCD Photometry for the Open Cluster NGC3532
• Disk Material Inflates Gaia RUWE Values in Single Stars
• wdwarfdate: A Python Package to Derive Bayesian Ages of White Dwarfs
• The Factory and the Beehive III: PTFEB132.707+19.810, a Low-Mass Eclipsing Binary in Praesepe Observed by PTF and K2
• Gyrochronological dating of the stellar moving group Group X
• Spectroscopic membership for the populous 300 Myr-old open cluster NGC 3532
• A Lyman-alpha transit left undetected: the environment and atmospheric behavior of K2-25b
• Commissioning ShARCS: the Shane Adaptive optics infraRed Camera-Spectrograph for the Lick Observatory 3-m telescope
• A 38 Million Year Old Neptune-Sized Planet in the Kepler Field
• The Flaring TESS Objects of Interest: Flare Rates for all Two Minute Cadence TESS Planet Candidates
• Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary

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• TESS Hunt for Young and Maturing Exoplanets (THYME) IX: a 27 Myr extended population of Lower-Centaurus Crux with a transiting two-planet system
• The MOPYS project: A survey of 70 planets in search of extended He I and H atmospheres. No evidence of enhanced evaporation in young planets
• Using the Gaia excess uncertainty as a proxy for stellar variability and age
• TOI-4562 b: A highly eccentric temperate Jupiter analog orbiting a young field star
• Hundreds of TESS exoplanets might be larger than we thought
• A rotational age for the open cluster NGC 2281
• Stellar obliquities of eight close-in gas giant exoplanets
• The cosmic waltz of Coma Berenices and Latyshev 2 (Group X). Membership, phase-space structure, mass, and energy distributions
• Contemporaneous Observations of $H\alpha$ Luminosities and Photometric Amplitudes for M Dwarfs
• A study of the frequency and characteristics of stellar companions and Jupiter-like planets in nearby open clusters
• Confirming the Tidal Tails of the Young Open Cluster Blanco 1 with TESS Rotation Periods
• A search for stellar siblings of the ~ 200 Myr TOI-251b planetary system