Related papers: Solar and stellar activity cycles -- no synchroniz…
Interactions between the winds of stars and the magnetospheres and atmospheres of planets involve many processes, including the acceleration of particles, heating of upper atmospheres, and a diverse range of atmospheric loss processes.…
We investigate the relations between tachocline-based dynamos and the surface flux transport mechanisms in stars with outer convection zones. Using our combined models of flux generation and transport, we demonstrate the importance of the…
Stellar magnetism, explorable via polarimetry, is a crucial driver of activity, ionization, photodissociation, chemistry and winds in stellar environments. Thus it has an important impact on the atmospheres and magnetospheres of surrounding…
There are several physical processes that mediate the interaction between an exoplanet and its host star, with the four main ones being due to magnetic, particle (stellar outflow), radiative and tidal interactions. These interactions can be…
Traditionally, the solar activity cycle is thought as an interplay of the main dipole component of the solar poloidal magnetic field and the toroidal magnetic field. However, the real picture as presented in the extended solar-cycle models…
Commenting the 11-year sunspot cycle, Wolf (1859, MNRAS 19, 85-86) conjectured that "the variations of spot frequency depend on the influences of Venus, Earth, Jupiter, and Saturn". The high synchronization of our planetary system is…
Simple models of magnetic field generation by convection in rotating spherical shells exhibit properties resembling those observed on the sun. The {assumption of the Boussinesq approximation made in these models} prevents a realistic…
Here, I review some recent works on magnetism of cool, main-sequence stars, their winds and potential impact on surrounding exoplanets. The winds of these stars are very tenuous and persist during their lifetime. Although carrying just a…
Observations show that faster-rotating stars tend to have stronger magnetic activity and shorter magnetic cycles. The cyclical magnetic activity of the Sun and stars is believed to be driven by the dynamo process. The success of the…
Magnetic field generation in the Sun and solar-type stars is modeled here based on the formation of magnetically polarized condensates (B. M. Mirza, Mod. Phys. Lett. B 28 (2014) 1450148) under the high density and pressure conditions. The…
Recent observations suggest that stellar magnetic activity may be influenced by the presence of a close-by giant planet. Specifically, chromospheric hot spots rotating in phase with the planet orbital motion have been observed during some…
Observations of magnetic activity cycles in other stars provide a broader context for our understanding of the 11-year sunspot cycle. The discovery of short activity cycles in a few stars, and the recognition of analogous variability in the…
The outflowing magnetized wind from a host star shapes planetary and exoplanetary magnetospheres dictating the extent of its impact. We carry out three-dimensional (3D) compressible magnetohydrodynamic (MHD) simulations of the interactions…
The discovery of now about 20 extrasolar planets orbiting solar-type stars with properties quite different from those in our Solar System has raised many questions about the formation and evolution of planets. The tidal interaction between…
Stellar magnetic activity of solar like stars is thought to be due to an internal dynamo. While the Sun has been the subject of intense research for refining dynamo models, observations of magnetic cyclic activity in solar type stars have…
A thermodynamic model for the generation of magnetic fields in the planets is proposed, considering crossed effects between gravitational and electric forces. The magnetic field of the Earth is estimated and found to be in agreement with…
Recent data from the Kepler mission has revealed the occurrence of superflares in sun-like stars which exceed by far any observed solar flares in release of energy. A natural idea is that the dynamo mechanism in superflaring stars differs…
The solar magnetic activity cycle is responsible for periodic episodes of severe space weather, which can perturb satellite orbits, interfere with communications systems, and bring down power grids. Much progress has recently been made in…
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 dynamo process is believed to drive the magnetic activity of stars like the Sun that have an outer convection zone. Large spectroscopic surveys showed that there is a relation between the rotation periods and the cycle periods: the…