TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

Abstract

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright ($T=8.5$ mag), high proper motion ($\sim 200$ mas yr${}^{-1}$), low metallicity ([Fe/H]$\approx -0.28$) K-dwarf with a mass of $0.68\pm 0.05$ M${}_{\odot }$ and a radius of $0.67\pm 0.01$ R${}_{\odot }$. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a $1.70\pm 0.07$ R${}_{\oplus }$ super-Earth in a 3.82 day orbit, placing it directly within the so-called 'radius valley'. The outer planet, TOI-836 c, is a $2.59\pm 0.09$ R${}_{\oplus }$ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of $4.5\pm 0.9$ M${}_{\oplus }$ , while TOI-836 c has a mass of $9.6\pm 2.6$ M${}_{\oplus }$. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet.

References in corpus (102)

• Astropy: A Community Python Package for Astronomy
• 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 Transiting Exoplanet Survey Satellite
• The No-U-Turn Sampler: Adaptively Setting Path Lengths in Hamiltonian Monte Carlo
• The K2 Mission: Characterization and Early results
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• The WASP Project and the SuperWASP Cameras
• Las Cumbres Observatory Global Telescope Network
• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• A new generation of PARSEC-COLIBRI stellar isochrones including the TP-AGB phase
• Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
• The Revised TESS Input Catalog and Candidate Target List
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• Elemental Abundance Survey of The Galactic Thick Disk
• The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
• The CoRoT satellite in flight : description and performance
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• Kepler planets: a tale of evaporation
• Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
• EXOFAST: A fast exoplanetary fitting suite in IDL
• 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
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program.Galactic stellar populations and planets
• Wide-field millimagnitude photometry with HAT: A Tool for Extra-solar Planet Detection
• Homogeneous studies of transiting extrasolar planets. IV. Thirty systems with space-based light curves
• The California Kepler Survey VII. Precise Planet Radii Leveraging Gaia DR2 Reveal the Stellar Mass Dependence of the Planet Radius Gap
• An asteroseismic view of the radius valley: stripped cores, not born rocky
• The LCES HIRES/Keck Precision Radial Velocity Exoplanet Survey
• Mass-Radius Relation for Rocky Planets based on PREM
• The Kilodegree Extremely Little Telescope (KELT): A Small Robotic Telescope for Large-Area Synoptic Surveys
• The TESS Objects of Interest Catalog from the TESS Prime Mission
• Three regimes of extrasolar planets inferred from host star metallicities
• STARRY: Analytic Occultation Light Curves
• Parametrizing the exoplanet eccentricity distribution with the Beta distribution
• Kepler Data Validation I -- Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
• A new list of thorium and argon spectral lines in the visible
• Almost All of Kepler's Multiple Planet Candidates are Planets
• SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs I. New atmospheric parameters and masses for 48 stars with planets
• Understanding The Effects Of Stellar Multiplicity On The Derived Planet Radii From Transit Surveys: Implications for Kepler, K2, and TESS
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• The CHEOPS mission
• The Next Generation Transit Survey (NGTS)
• Compositional imprints in density-distance-time: a rocky composition for close-in low-mass exoplanets from the location of the valley of evaporation
• Planetary nebulae seen with TESS: Discovery of new binary central star candidates from Cycle 1
• The Kepler Follow-Up Observation Program. I. A Catalog of Companions to Kepler Stars from High-Resolution Imaging
• CLES, Code Liegeois d'Evolution Stellaire
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• SOAR TESS Survey. I: Sculpting of TESS planetary systems by stellar companions
• Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity
• ARES v2 - new features and improved performance
• HATSouth: a global network of fully automated identical wide-field telescopes
• Atmospheric Mass Loss During Planet Formation: The Importance of Planetesimal Impacts
• Six transiting planets and a chain of Laplace resonances in TOI-178
• The statistics of multi-planet systems
• Kepler Multi-Planet Systems Exhibit Unexpected Intra-system Uniformity in Mass and Radius
• Evolution of the radius valley around low mass stars from $Kepler$ and $K2$
• Determining the Mass of Kepler-78b With Nonparametric Gaussian Process Estimation
• Analytic Planetary Transit Light Curves and Derivatives for Stars with Polynomial Limb Darkening
• WASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V star
• High-resolution imaging of $Kepler$ planet host candidates. A comprehensive comparison of different techniques
• Expected performances of the Characterising Exoplanet Satellite (CHEOPS) III. Data reduction pipeline: architecture and simulated performances
• Age consistency between exoplanet hosts and field stars
• Revising the ages of planet-hosting stars
• Can planetary instability explain the Kepler dichotomy?
• Comparing HARPS and Kepler surveys: The alignment of multiple-planet systems
• A Spectroscopic Analysis of the California-Kepler Survey Sample: I. Stellar Parameters, Planetary Radii and a Slope in the Radius Gap
• Minerva-Australis I: Design, Commissioning, & First Photometric Results
• An Earth-sized exoplanet with a Mercury-like composition
• EXOFASTv2: A public, generalized, publication-quality exoplanet modeling code
• SWEET-Cat 2.0: The Cat just got SWEETer; Higher quality spectra and precise parallaxes from GAIA eDR3
• The hot dayside and asymmetric transit of WASP-189b seen by CHEOPS
• Multiplicity in transiting planet host stars. A Lucky Imaging study of Kepler candidates
• The Monitor project: Data processing and lightcurve production
• Masses and compositions of three small planets orbiting the nearby M dwarf L231-32 (TOI-270) and the M dwarf radius valley
• Transit detection of the long-period volatile-rich super-Earth ${\nu }^2$ Lupi d with $CHEOPS$
• CHEOPS observations of the HD 108236 planetary system: A fifth planet, improved ephemerides, and planetary radii
• The secondary eclipses of WASP-19b as seen by the ASTEP 400 telescope from Antarctica
• Identifying the best iron-peak and $\alpha$-capture elements for chemical tagging: The impact of the number of lines on measured scatter
• Diving Beneath the Sea of Stellar Activity: Chromatic Radial Velocities of the Young AU Mic Planetary System
• WASP-186 and WASP-187: two hot Jupiters discovered by SuperWASP and SOPHIE with additional observations by TESS
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program IV. Carbon and C/O ratios for Galactic stellar populations and planet hosts
• A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS
• Reinvestigating $\alpha$ Cen AB in light of asteroseismic forward and inverse methods
• Simultaneous TESS and NGTS Transit Observations of WASP-166b
• TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
• TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet
• TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
• Planets Across Space and Time (PAST). I. Characterizing the Memberships of Galactic Components and Stellar Ages: Revisiting the Kinematic Methods and Applying to Planet Host Stars
• The Magellan-TESS Survey I: Survey Description and Mid-Survey Results
• Thermalizing a telescope in Antarctica: Analysis of ASTEP observations
• Validation of 13 Hot and Potentially Terrestrial TESS Planets
• Planets Across Space and Time (PAST). III. Morphology of the Planetary Radius Valley as a Function of Stellar Age and Metallicity in the Galactic Context Revealed by the LAMOST-Gaia-Kepler Sample
• ASTEP South: An Antarctic Search for Transiting ExoPlanets around the celestial South pole
• Shallow transit follow-up from NGTS: simultaneous observations of HD106315 with 11 identical telescopes
• Photo-Dynamical Analysis of Three Kepler Objects of Interest with Significant Transit Timing Variations
• Four winters of photometry with ASTEP South at Dome C, Antarctica
• Split Peas in a Pod: Intra-System Uniformity of Super-Earths and Sub-Neptunes

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• Shallower radius valley around low-mass hosts: Evidence for icy planets, collisions or high-energy radiation scatter
• The SOPHIE search for northern extrasolar planets-XIX. A system including a cold sub-Neptune potentially transiting a V = 6.5 star HD88986
• Characterisation of TOI-406 as showcase of the THIRSTEE program: A 2-planet system straddling the M-dwarf density gap
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• The inflated, eccentric warm Jupiter TOI-4914 b orbiting a metal-poor star, and the hot Jupiters TOI-2714 b and TOI-2981 b
• Not All Sub-Neptune Exoplanets Have Magma Oceans
• A Pair of Dynamically Interacting Sub-Neptunes Around TOI-6054
• Homogeneous search for spot transits in Kepler and TESS photometry of K $-$ M-type main-sequence stars
• Gas-depleted planet formation occurred in the four-planet system around the red dwarf LHS 1903
• Sub-Neptunes as Soot Factories: Deep Atmosphere Hydrocarbon Formation and Quenching as the Origin of Sub-Neptune Aerosol Trends
• Impact of Clouds on the Atmosphere-Mantle Interface of Sub-Neptunes