K2-290: a warm Jupiter and a mini-Neptune in a triple-star system

Abstract

We report the discovery of two transiting planets orbiting K2-290 (EPIC 249624646), a bright (V=11.11) late F-type star residing in a triple-star system. It was observed during Campaign 15 of the K2 mission, and in order to confirm and characterise the system, follow-up spectroscopy and AO imaging were carried out using the FIES, HARPS, HARPS-N, and IRCS instruments. From AO imaging and Gaia data we identify two M-dwarf companions at a separation of $113\pm 2$ AU and $2467_{-155}^{+177}$ AU. From radial velocities, K2 photometry, and stellar characterisation of the host star, we find the inner planet to be a mini-Neptune with a radius of $3.06\pm 0.16R_{\oplus }$ and an orbital period of $P=9.2$ days. The radius of the mini-Neptune suggests that the planet is located above the radius valley, and with an incident flux of $F\sim 400F_{\oplus }$, it lies safely outside the super-Earth desert. The outer warm Jupiter has a mass of $0.774\pm 0.047M_{\mathrm{J}}$ and a radius of $1.006\pm 0.050R_{\mathrm{J}}$, and orbits the host star every 48.4 days on an orbit with an eccentricity $e<0.241$. Its mild eccentricity and mini-Neptune sibling suggest that the warm Jupiter originates from in situ formation or disk migration.

arXiv comment16 pages, 8 figures, accepted for publication in MNRAS. Updated to accepted version (including K2 name)

References in corpus (59)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Transiting Exoplanet Survey Satellite
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Analytic Lightcurves for Planetary Transit Searches
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The K2 Mission: Characterization and Early results
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• batman: BAsic Transit Model cAlculatioN in Python
• Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits
• Kepler Input Catalog: Photometric Calibration and Stellar Classification
• No planet for HD 166435
• EXOFAST: A fast exoplanetary fitting suite in IDL
• Hot Stars with Hot Jupiters Have High Obliquities
• Gaia Data Release 2: using Gaia parallaxes
• Modelling the Galactic Interstellar Extinction Distribution in Three Dimensions
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• Origins of Hot Jupiters
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• The Mass-Radius Relation for 65 Exoplanets Smaller than 4 Earth Radii
• The CORALIE survey for southern extra-solar planets VII. Two short-period Saturnian companions to HD108147 and HD168746
• An asteroseismic view of the radius valley: stripped cores, not born rocky
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• Improving the Efficiency of Markov Chain Monte Carlo for Analyzing the Orbits of Extrasolar Planets
• Galactic Reddening in 3D from Stellar Photometry - An Improved Map
• On the use of empirical bolometric corrections for stars
• The Mass-Metallicity Relation for Giant Planets
• Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology
• The GAPS Programme with HARPS-N@TNG XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets
• The Updated BaSTI Stellar Evolution Models and Isochrones: I. Solar Scaled Calculations
• Atmospheres of protoplanetary cores: critical mass for nucleated instability
• Eccentricity from transit photometry: small planets in Kepler multi-planet systems have low eccentricities
• Synthetic Stellar Photometry - I. General considerations and new transformations for broad-band systems
• In Situ Formation and Dynamical Evolution of Hot Jupiter Systems
• Hot super-Earths stripped by their host stars
• Lack of Inflated Radii for Kepler Giant Planet Candidates Receiving Modest Stellar Irradiation
• The orbital eccentricity of small planet systems
• Giant planets orbiting metal-rich stars show signatures of planet-planet interactions
• An ancient extrasolar system with five sub-Earth-size planets
• Warm Jupiters are less lonely than hot Jupiters: close neighbours
• A planetary system around the nearby M dwarf GJ 667C with at least one super-Earth in its habitable zone
• Warm Jupiters from secular planet-planet interactions
• WASP-30b: a 61 Mjup brown dwarf transiting a V=12, F8 star
• The destruction of inner planetary systems during high-eccentricity migration of gas giants
• Warm Jupiters Need Close "Friends" for High-Eccentricity Migration -- A Stringent Upper Limit on the Perturber's Separation
• Bayesian analysis of radial velocity data of GJ667C with correlated noise: evidence for only 2 planets
• Synthetic Stellar Photometry - II. Testing the bolometric flux scale, and tables of bolometric corrections for the Hipparcos/Tycho, Pan-STARRS1, SkyMapper and JWST systems
• New prospects for observing and cataloguing exoplanets in well detached binaries
• 44 Validated Planets from K2 Campaign 10
• The discovery and mass measurement of a new ultra-short-period planet: EPIC~228732031b
• Eccentricities and Inclinations of Multi-Planet Systems with External Perturbers
• A High Stellar Obliquity in the WASP-7 Exoplanetary System
• K2-260 b: a hot Jupiter transiting an F star, and K2-261 b: a warm Saturn around a bright G star
• Kepler-77b: a very low albedo, Saturn-mass transiting planet around a metal-rich solar-like star
• Effects of Disk Warping on the Inclination Evolution of Star-Disk-Binary Systems
• HD 89345: a bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2
• The K2-ESPRINT Project III: A Close-in Super-Earth around a Metal-rich Mid-M Dwarf
• The K2-ESPRINT Project IV: A Hot Jupiter in a Prograde Orbit with a Possible Stellar Companion
• On the formation of hot and warm Jupiters via secular high-eccentricity migration in stellar triples

Cited by in corpus (20)

• Stellar obliquities in exoplanetary systems
• A Preponderance of Perpendicular Planets
• A backward-spinning star with two coplanar planets
• The BAyesian STellar Algorithm (BASTA): a fitting tool for stellar studies, asteroseismology, exoplanets, and Galactic archaeology
• TOI-503: The first known brown dwarf-Am star binary from the TESS mission
• TESS spots a mini-neptune interior to a hot saturn in the TOI-2000 system
• Planetary system around LTT 1445A unveiled by ESPRESSO: Multiple planets in a triple M-dwarf system
• Resonant sub-Neptunes are puffier
• TOI-2046b, TOI-1181b and TOI-1516b, three new hot Jupiters from \textit{TESS}: planets orbiting a young star, a subgiant and a normal star
• TOI-1670 b and c: An Inner Sub-Neptune with an Outer Warm Jupiter Unlikely to have Originated from High-Eccentricity Migration
• The chaotic history of the retrograde multi-planet system in K2-290A driven by distant stars
• Greening of the Brown Dwarf Desert. EPIC 212036875 b -- a 51 M${}_{\mathrm{J}}$ object in a 5 day orbit around an F7 V star
• An Early Catalog of Planet Hosting Multiple Star Systems of Order Three and Higher
• A highly mutually-inclined, compact warm-Jupiter system KOI-984 ?
• K2-280b -- a low density warm sub-Saturn around a mildly evolved star
• Evidence for Primordial Alignment II: Insights from Stellar Obliquity Measurements for Hot Jupiters in Compact Multiplanet Systems
• True spin-orbit obliquities distribution: data-driven confirmation of no clustering of misaligned planets
• Flows, Circulations, and Energy Transport in the Outer and Deep Atmospheres of Synchronous and Non-synchronous Hot Jupiters
• POSEIDON II: The Anti-Aligned Orbit of the Warm Neptune TOI-1710 A b
• Search for (sub)stellar companions of exoplanet hosts by exploring the second ESA-Gaia data release