K2-260 b: a hot Jupiter transiting an F star, and K2-261 b: a warm Saturn around a bright G star

Abstract

We present the discovery and confirmation of two new transiting giant planets from the Kepler extended mission K2. K2-260 b is a hot Jupiter transiting a $V=12.7$ F6V star in K2 Field 13, with a mass and radius of $M_{\star }=1.39_{-0.06}^{+0.05}{M}_{\odot }$ and $R_{\star }=1.69\pm 0.03R_{\odot }$. The planet has an orbital period of $P=2.627$ days, and a mass and radius of $M_P=1.42_{-0.32}^{+0.31}{M}_J$ and $R_P=1.552_{-0.057}^{+0.048}{R}_J$. This is the first K2 hot Jupiter with a detected secondary eclipse in the Kepler bandpass, with a depth of $71\pm 15$ ppm, which we use to estimate a geometric albedo of $A_g\sim 0.2$. We also detected a candidate stellar companion at 0.6" from K2-260; we find that it is very likely physically associated with the system, in which case it would be an M5-6V star at a projected separation of $\sim 400$ AU. K2-261 b is a warm Saturn transiting a bright ($V=10.5$) G7IV/V star in K2 Field 14. The host star is a metal-rich ([Fe/H]$=0.36\pm 0.06$), mildly evolved $1.10_{-0.02}^{+0.01}{M}_{\odot }$ star with $R_{\star }=1.65\pm 0.04R_{\odot }$. Thanks to its location near the main sequence turn-off, we can measure a relatively precise age of $8.8_{-0.3}^{+0.4}$ Gyr. The planet has $P=11.633$ days, $M_P=0.223\pm 0.031M_J$, and $R_P=0.850_{-0.022}^{+0.026}{R}_J$, and its orbit is eccentric ($e=0.39\pm 0.15$). Its brightness and relatively large transit depth make this one of the best known warm Saturns for follow-up observations to further characterize the planetary system.

arXiv commentPublished in MNRAS. 18 pages, 10 figures

References in corpus (74)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Gaia mission
• 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
• The K2 Mission: Characterization and Early results
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• Astrophysics Source Code Library
• batman: BAsic Transit Model cAlculatioN in Python
• A box-fitting algorithm in the search for periodic transits
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• Elemental Abundance Survey of The Galactic Thick Disk
• Hot Stars with Hot Jupiters Have High Obliquities
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• Modelling the Galactic Interstellar Extinction Distribution in Three Dimensions
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• The CORALIE survey for southern extra-solar planets VII. Two short-period Saturnian companions to HD108147 and HD168746
• RadVel: The Radial Velocity Modeling Toolkit
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• Galactic Reddening in 3D from Stellar Photometry - An Improved Map
• Spin-orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters
• False positive probabilties for all Kepler Objects of Interest: 1284 newly validated planets and 428 likely false positives
• Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology
• Terrestrial Planet Occurrence Rates for the Kepler GK Dwarf Sample
• The Kepler characterization of the variability among A- and F-type stars. I. General overview
• Prospects for the Characterization and Confirmation of Transiting Exoplanets via the Rossiter-McLaughlin Effect
• The Stellar Populations of Praesepe and Coma Berenices
• The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8
• On the Formation of Hot Jupiters in Stellar Binaries
• Stellar Limb-Darkening Coefficients for CoRot and Kepler
• Determining stellar macroturbulence using asteroseismic rotational velocities from Kepler
• Magnetic cycles of the planet-hosting star tauBootis
• Optical Phase Curves of Kepler Exoplanets
• 275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0-10
• Confirming chemical clocks: asteroseismic age dissection of the Milky Way disk(s)
• Understanding Trends Associated with Clouds in Irradiated Exoplanets
• Photometric Amplitude Distribution of Stellar Rotation of Kepler KOIs-Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars
• Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
• An ultra-short period rocky super-Earth with a secondary eclipse and a Neptune-like companion around K2-141
• Discerning Exoplanet Migration Models Using Spin-Orbit Measurements
• Four Sub-Saturns with Dissimilar Densities: Windows into Planetary Cores and Envelopes
• Hierarchical Bayesian calibration of tidal orbit decay rates among hot Jupiters
• The transiting multi-planet system HD3167: a 5.7 MEarth Super-Earth and a 8.3 MEarth mini-Neptune
• Evolution of angular-momentum-losing exoplanetary systems : Revisiting Darwin stability
• The discovery and mass measurement of a new ultra-short-period planet: EPIC~228732031b
• Three Small Super-Earths Transiting the nearby star GJ 9827
• Photospheric activity and rotation of the planet-hosting star CoRoT-Exo-4a
• Kepler423b: a half-Jupiter mass planet transiting a very old solar-like star
• Doppler Monitoring of five K2 Transiting Planetary Systems
• A study of the performance of the transit detection tool DST in space-based surveys. Application of the CoRoT pipeline to Kepler data
• K2-137 b: an Earth-sized planet in a 4.3-hour orbit around an M-dwarf
• HD 89345: a bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2
• K2-99: a subgiant hosting a transiting warm Jupiter in an eccentric orbit and a long-period companion
• The K2-ESPRINT Project III: A Close-in Super-Earth around a Metal-rich Mid-M Dwarf
• KELT-21b: A Hot Jupiter Transiting the Rapidly-Rotating Metal-Poor Late-A Primary of a Likely Hierarchical Triple System
• Discovery of the secondary eclipse of HAT-P-11 b
• Spin-Orbit Misalignments of Three Jovian Planets via Doppler Tomography
• EPIC247098361b: a transiting warm Saturn on an eccentric $P=11.2$ days orbit around a $V=9.9$ star
• Kea: a new tool to obtain stellar parameters from low to moderate signal/noise and high-resolution Echelle spectra
• The K2-ESPRINT Project IV: A Hot Jupiter in a Prograde Orbit with a Possible Stellar Companion
• Two Hot Jupiters from K2 Campaign 4
• K2-31b, a grazing transiting hot Jupiter on an 1.26-day orbit around a bright G7V star
• Average Albedos of Close-in Super-Earths and Neptunes from Statistical Analysis of Long Cadence Kepler Secondary Eclipse Data
• The DEdicated MONitor of EXotransits and Transients (DEMONEXT): System Overview and Year One Results from a Low-Cost Robotic Telescope for Follow-Up of Exoplanetary Transits and Transients
• K2-113b: A dense hot-Jupiter transiting a solar analogue
• The K2-ESPRINT Project VI: K2-105 b, a Hot-Neptune around a Metal-rich G-dwarf
• Constraints on the Obliquities of Kepler Planet-Hosting Stars

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