Effect of stellar wind induced magnetic fields on planetary obstacles of non-magnetized hot Jupiters

Abstract

We investigate the interaction between the magnetized stellar wind plasma and the partially ionized hydrodynamic hydrogen outflow from the escaping upper atmosphere of non- or weakly magnetized hot Jupiters. We use the well-studied hot Jupiter HD 209458b as an example for similar exoplanets, assuming a negligible intrinsic magnetic moment. For this planet, the stellar wind plasma interaction forms an obstacle in the planet's upper atmosphere, in which the position of the magnetopause is determined by the condition of pressure balance between the stellar wind and the expanded atmosphere, heated by the stellar extreme ultraviolet (EUV) radiation. We show that the neutral atmospheric atoms penetrate into the region dominated by the stellar wind, where they are ionized by photo-ionization and charge exchange, and then mixed with the stellar wind flow. Using a 3D magnetohydrodynamic (MHD) model, we show that an induced magnetic field forms in front of the planetary obstacle, which appears to be much stronger compared to those produced by the solar wind interaction with Venus and Mars. Depending on the stellar wind parameters, because of the induced magnetic field, the planetary obstacle can move up to ~0.5-1 planetary radii closer to the planet. Finally, we discuss how estimations of the intrinsic magnetic moment of hot Jupiters can be inferred by coupling hydrodynamic upper planetary atmosphere and MHD stellar wind interaction models together with UV observations. In particular, we find that HD 209458b should likely have an intrinsic magnetic moment of 10-20% that of Jupiter.

arXiv comment8 pages, 6 figures, 2 tables, accepted to MNRAS

References in corpus (37)

• Atmospheric Escape from Hot Jupiters
• Planetary evaporation by UV & X-ray radiation: basic hydrodynamics
• Homogeneous studies of transiting extrasolar planets. III. Additional planets and stellar models
• The escape of heavy atoms from the ionosphere of HD209458b. I. A photochemical-dynamical model of the thermosphere
• Simulating the escaping atmospheres of hot gas planets in the solar neighborhood
• Predicting low-frequency radio fluxes of known extrasolar planets
• Is Proxima Centauri b habitable? -- A study of atmospheric loss
• Classification of magnetized star--planet interactions: bow shocks, tails, and inspiraling flows
• On the existence of energetic atoms in the upper atmosphere of exoplanet HD209458b
• XUV-driven mass loss from extrasolar giant planets orbiting active stars
• Magnetically controlled mass loss from extrasolar planets in close orbits
• 3D Gas Dynamic Simulation of the Interaction Between the Exoplanet WASP-12b and Its Host Star
• Magnetically Controlled Outflows from Hot Jupiters
• Hot Jupiter Magnetospheres
• Heating efficiency in hydrogen-dominated upper atmospheres
• The Dynamics of Stellar Coronae Harboring Hot-jupiters I. A Time-dependent MHD Simulation of the Interplanetary Environment in the HD 189733 Planetary System
• Aeronomical constraints to the minimum mass and maximum radius of hot low-mass planets
• Atmosphere Expansion and Mass Loss of Close-Orbit Giant Exoplanets heated by Stellar XUV. II. Effects of Planetary Magnetic Field, Structuring of inner Magnetosphere
• Stellar Winds on the Main-Sequence I: Wind Model
• Colliding Planetary and Stellar Winds: Charge Exchange and Transit Spectroscopy in Neutral Hydrogen
• The escape of heavy atoms from the ionosphere of HD209458b. II. Interpretation of the observations
• Magnetohydrodynamic Simulations of Hot Jupiter Upper Atmospheres
• Atmosphere expansion and mass loss of close-orbit giant exoplanets heated by stellar XUV: I. Modeling of hydrodynamic escape of upper atmospheric material
• Escaping Particle fluxes in the atmospheres of close-in exoplanets: I. model of hydrogen
• Thermal mass loss of protoplanetary cores with hydrogen-dominated atmospheres: The influences of ionization and orbital distance
• Anisotropic winds from close-in extra-solar planets
• The Interaction of Venus-like, M-dwarf Planets with the Stellar Wind of Their Host Star
• Stellar wind interaction and pick-up ion escape of the Kepler-11 "super-Earths"
• Identifying the "true" radius of the hot sub-Neptune CoRoT-24b by mass loss modelling
• XUV exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets II: Hydrogen coronae and ion escape
• Two regimes of interaction of a Hot Jupiter's escaping atmosphere with the stellar wind and generation of energized atomic hydrogen corona
• An Overabundance of Low-density Neptune-like Planets
• How Expanded Ionospheres of Hot Jupiters Can Prevent Escape of Radio Emission Generated by the Cyclotron Maser Instability
• The influence of the Extreme Ultraviolet spectral energy distribution on the structure and composition of the upper atmosphere of exoplanets
• Axisymmetric Simulations of Hot Jupiter-Stellar Wind Hydrodynamic Interaction
• EUV-driven ionospheres and electron transport on extrasolar giant planets orbiting active stars
• Extrasolar giant magnetospheric response to steady-state stellar wind pressure at 10, 5, 1, and 0.2 AU

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