相关论文: Planetary Magnetic Field Control of Ion Escape fro…
Planetary habitability is in part determined by the atmospheric evolution of a planet; one key component of such evolution is escape of heavy ions to space. Ion loss processes are sensitive to the plasma environment of the planet, dictated…
The extent to which a magnetosphere protects its planetary atmosphere from stellar wind ablation depends upon how well it prevents energy and momentum exchange with the atmosphere and how well it traps otherwise escaping plasma. We focus on…
Hot Jupiters can experience mass loss driven by heating from UV radiation from their host stars, and this flow is often controlled by magnetic fields. More specifically, near the planetry surface, the magnetic pressure dominates the ram…
We consider the role magnetic fields play in guiding and controlling mass-loss via evaporative outflows from exoplanets that experience UV irradiation. First we present analytic results that account for planetary and stellar magnetic…
(abridged abstract) Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields, especially in the case of planets more massive than Earth (super-Earths). Planetary magnetic fields, however, constitute…
Stellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and…
Using 3D radiative MHD simulations and Lyman-$\alpha$ transit calculations, we investigate the effect of magnetic fields on the observational signatures of atmospheric escape in exoplanets. Using the same stellar wind, we vary the planet's…
The magnetic activity of a star -- which modulates the stellar wind outflow -- shapes the immediate environments of orbiting planets and induces atmospheric loss thereby impacting their habitability. We perform a detailed parameter space…
The magnetospheric emissions from extrasolar planets represent a science frontier for the next decade. All of the solar system giant planets and the Earth produce radio emissions as a result of interactions between their magnetic fields and…
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…
We propose a new method to estimate ion escape from unmagnetized planets that combines observations and models. Assuming that upstream solar wind conditions are known, a computer model of the interaction between the solar wind and the…
We explore ion escape from, and solar ion deposition to, \hll{an unmagnetized Earth-like planet}. We use RHybrid, an ion-kinetic electron-fluid code to simulate the global plasma interaction of unmagnetized Earth with the solar wind. We…
The Earth is a planet with a dipolar magnetic field which is agitated by a magnetized plasma wind streaming from the Sun. The magnetic field shields the Earth's surface from penetrating high energy solar wind particles, as well as…
Atmospheric mass-loss from Hot-jupiters can be large due to the close proximity of these planets to their host star and the strong radiation the planetary atmosphere receives. On Earth, a major contribution to the acceleration of…
The intrinsic magnetic fields of exoplanets affect the structure of their atmospheres and plasmaspheres and, therefore, the observational manifestations of transit absorptions. This work proposes a new method for constraining the presence…
Exoplanetary and planetary environments are forced by stellar activity which manifest through variable radiation, particle and magnetic fluxes, stellar winds, flares and magnetic storms known as coronal mass ejections (CMEs). Recent studies…
Recent results showed that the magnetic field of M-dwarf (dM) stars, currently the main targets in searches for terrestrial planets, is very different from the solar one, both in topology as well as in intensity. In particular, the…
The atmospheres of highly irradiated exoplanets are observed to undergo hydrodynamic escape. However, due to strong pressures, stellar winds can confine planetary atmospheres, reducing their escape. Here, we investigate under which…
Mars lacks a global intrinsic dipole magnetic field, but its interaction with the solar wind generates a global induced magnetosphere. Until now, most studies have relied on single-spacecraft measurements, which could not simultaneously…
The absence of global magnetic fields is often cited to explain why Mars lacks a dense atmosphere. This line of thought is based on a prevailing theory that magnetic fields can shield the atmosphere from solar wind erosion. However, we…