The discoveries of WASP-91b, WASP-105b and WASP-107b: two warm Jupiters and a planet in the transition region between ice giants and gas giants

Abstract

We report the discoveries of three transiting exoplanets. WASP-91b is a warm Jupiter (1.34 $M_{\mathrm{Jup}}$, 1.03 $R_{\mathrm{Jup}}$) in a 2.8-day orbit around a metal-rich K3 star. WASP-105b is a warm Jupiter (1.8 $M_{\mathrm{Jup}}$, 0.96 $R_{\mathrm{Jup}}$) in a 7.9-day orbit around a metal-rich K2 star. WASP-107b is a warm super-Neptune/sub-Saturn (0.12 $M_{\mathrm{Jup}}$, 0.94 $R_{\mathrm{Jup}}$) in a 5.7-day orbit around a solar-metallicity K6 star. Considering that giant planets seem to be more common around stars of higher metallicity and stars of higher mass, it is notable that the hosts are all metal-rich, late-type stars. With orbital separations that place both WASP-105b and WASP-107b in the weak-tide regime, measurements of the alignment between the planets' orbital axes and their stars' spin axes may help us to understand the inward migration of short-period, giant planets. The mass of WASP-107b (2.2 $M_{\mathrm{Nep}}$, 0.40 $M_{\mathrm{Sat}}$) places it in the transition region between the ice giants and gas giants of the Solar System. Its radius of 0.94 $R_{\mathrm{Jup}}$ suggests that it is a low-mass gas giant with a H/He-dominated composition. The planet thus sets a lower limit of 2.2 $M_{\mathrm{Nep}}$ on the planetary mass above which large gaseous envelopes can be accreted and retained by proto-planets on their way to becoming gas giants. We may discover whether WASP-107b more closely resembles an ice giant or a gas giant by measuring its atmospheric metallicity via transmission spectroscopy, for which WASP-107b is a very good target.

As accepted by A&A. http://adsabs.harvard.edu/abs/2017A%26A...604A.110A. 9 pages, 6 figures, 4 table

References in corpus (12)

• The K2 Mission: Characterization and Early results
• The Transiting Circumbinary Planets Kepler-34 and Kepler-35
• Separating gas-giant and ice-giant planets by halting pebble accretion
• A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b
• Efficient identification of exoplanetary transit candidates from SuperWASP light curves
• A fast hybrid algorithm for exoplanetary transit searches
• WASP-42 b and WASP-49 b: two new transiting sub-Jupiters
• WASP-South transiting exoplanets: WASP-130b, WASP-131b, WASP-132b, WASP-139b, WASP-140b, WASP-141b & WASP-142b
• The Formation of Uranus & Neptune: Challenges and Implications For Intermediate-Mass Exoplanets
• TRADES: A new software to derive orbital parameters from observed transit times and radial velocities. Revisiting Kepler-11 and Kepler-9
• Bayesian mass and age estimates for transiting exoplanet host stars
• The well-aligned orbit of WASP-84b: evidence for disc migration

Cited by in corpus (70)

• Growth Model Interpretation of Planet Size Distribution
• Helium in the eroding atmosphere of an exoplanet
• Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
• Revisited Mass-Radius relations for exoplanets below 120 Earth masses
• Stellar obliquities in exoplanetary systems
• Habitability and Biosignatures of Hycean Worlds
• High-resolution confirmation of an extended helium atmosphere around WASP-107b
• Connecting Giant Planet Atmosphere and Interior Modeling: Constraints on Atmospheric Metal Enrichment
• SO2, silicate clouds, but no CH4 detected in a warm Neptune
• A High Internal Heat Flux and Large Core in a Warm Neptune Exoplanet
• Helium Absorption at 1083 nm from Extended Exoplanet Atmospheres: Dependence on Stellar Radiation
• He I $\lambda$ 10830 Å in the transmission spectrum of HD 209458 b
• TESS Transit Timing of Hundreds of Hot Jupiters
• A Preponderance of Perpendicular Planets
• WASP-107b's density is even lower: a case study for the physics of planetary gas envelope accretion and orbital migration
• A warm Neptune's methane reveals core mass and vigorous atmospheric mixing
• The occurrence rate of giant planets orbiting low-mass stars with TESS
• Confirmation of WASP-107b's extended Helium atmosphere with Keck II/NIRSPEC
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• DREAM I. Orbital architecture orrery
• Grid of Pseudo-2D Chemistry Models for Tidally-Locked Exoplanets. I. The Role of Vertical and Horizontal Mixing
• Tidal Inflation Reconciles Low-Density Sub-Saturns with Core Accretion
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• The TESS-Keck Survey IV: A Retrograde, Polar Orbit for the Ultra-Low-Density, Hot Super-Neptune WASP-107b
• Stellar Wind Confinement of Evaporating Exoplanet Atmospheres and its Signatures in 1083 nm Observations
• The discovery of WASP-151b, WASP-153b, WASP-156b: Insights on giant planet migration and the upper boundary of the Neptunian desert
• The post-transit tail of WASP-107b observed at 10830A
• A Jovian planet in an eccentric 11.5 day orbit around HD1397 discovered by TESS
• Starspots on WASP-107 and pulsations of WASP-118
• Metastable Helium Reveals an Extended Atmosphere for the Gas Giant HAT-P-18b
• Metastable Helium Absorptions with 3D Hydrodynamics and Self-Consistent Photochemistry II: WASP-107b, Stellar Wind, Radiation Pressure, and Shear Instability
• From cold to hot irradiated gaseous exoplanets: Toward an observation-based classification scheme
• A Search for FeH in Hot-Jupiter Atmospheres with High-Dispersion Spectroscopy
• ExoClock Project: An open platform for monitoring the ephemerides of Ariel targets with contributions from the public
• The GAPS Programme at TNG. XXXII. The revealing non-detection of metastable HeI in the atmosphere of the hot Jupiter WASP-80b
• WASP-166b: a bloated super-Neptune transiting a V = 9 star
• An Unusual Transmission Spectrum for the Sub-Saturn KELT-11b Suggestive of a Sub-Solar Water Abundance
• Cleaning our Hazy Lens: Exploring Trends in Transmission Spectra of Warm Exoplanets
• Evidence for Morning-to-Evening Limb Asymmetry on the Cool Low-Density Exoplanet WASP-107b
• Phase curve pollution of exoplanet transmission spectra
• Connection between planetary He I $\lambda$10830 Å absorption and extreme-ultraviolet emission of planet-host stars
• Exoplanet Interior Retrievals: core masses and metallicities from atmospheric abundances
• Are WASP-107-like Systems Consistent with High-eccentricity Migration?
• Simulation of 10830 Å absorption with a 3D hydrodynamic model reveals the solar He abundance in upper atmosphere of WASP-107b
• On the origin of the non-detection of metastable HeI in the upper atmosphere of the hot Jupiter WASP-80b
• Three Hot-Jupiters on the upper edge of the mass-radius distribution: WASP-177, WASP-181 and WASP-183
• TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter
• Elemental Abundances of the Super-Neptune WASP-107b's Host Star Using High-resolution, Near-infrared Spectroscopy
• TOI-1259Ab -- a gas giant planet with 2.7% deep transits and a bound white dwarf companion
• HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short Period Transiting Giant Planets in the Neptune-Jupiter Mass Range
• EPIC 201498078b: A low density Super Neptune on an eccentric orbit
• Planetary parameters, XUV environments and mass-loss rates for nearby gaseous planets with X-ray detected host-stars
• So close, so different: characterization of the K2-36 planetary system with HARPS-N
• Non-detection of Helium in the Hot Jupiter WASP-48b
• Why heterogeneous cloud particles matter: Iron-bearing species and cloud particle morphology affects exoplanet transmission spectra
• Prospects for Detecting Signs of Life on Exoplanets in the JWST Era
• A Panchromatic Characterization of the Evening and Morning Atmosphere of WASP-107 b: Composition and Cloud Variations, and Insight into the Effect of Stellar Contamination
• A third star in the HAT-P-7 system, and a new dynamical pathway to misaligned hot Jupiters
• NGTS-12b: A sub-Saturn mass transiting exoplanet in a 7.53 day orbit
• A Search for Exoplanets in Open Clusters and Young Associations based on TESS Objects of Interest
• TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with HPF
• A highly mutually-inclined, compact warm-Jupiter system KOI-984 ?
• An Analytic Characterization of the Limb Asymmetry -- Transit Time Degeneracy
• Detection of CO${}_2$, CO, and H${}_2$O in the atmosphere of the warm sub-Saturn HAT-P-12b
• Evidence for a Nonzero Eccentricity Superpuff Exoplanet WASP-107 b Using JWST Occultation Observation
• Homogeneous search for spot transits in Kepler and TESS photometry of K $-$ M-type main-sequence stars
• Reliability of 1D radiative-convective photochemical-equilibrium retrievals on transit spectra of WASP-107b
• A Cloudy Fit to the Atmosphere of WASP-107 b
• Grain Growth in Escaping Atmospheres: Implications for the Radius Inflation of Super-Puffs
• A Multi-Planet System's Sole Super-Puff: Exploring Allowable Physical Parameters for the Cold Super-Puff HIP 41378 f