We discuss how the lower corona may be connected to the chromospheric network pattern throughmagnetic funnels at the boundaries of the chromospheric network. At the feet of these funnels are located thin ionizing layers. The steady-state flow and temperature structure in the funnels is analyzed on the basis of the continuity of downward electron heat flux from the coronal base and the upward ad...

Faraclay rotation observations are unique amongst radio occultation mcasurcmcnts in that they respond to magnetic field in addition to e.lcctron density, making it possible to probe the coronal magnetic field. Transients observed by Pioneer 6 Faraday rotation measurements in 1968 in the heliocentric distance range of 6-11 R. arc shown to be caused by the radially expanding coronal streamer stal...

The amount of solar wind absorption due to charge-exchange in the Martian magnetosheath is evaluated and found to be about an order of magnitude less than that in the Venus magnetosheath. This difference might explain the observed difference in the scaled position and shape between the shocks at Venus and Mars. The lower solar wind absorption for Mars is attributable to the less dense hot oxyge...

We present a method for computing the net transmission of X-rays emitted by shock-heated plasma distributed throughout a partially optically thick stellar wind from a massive star. We find the transmission by an exact integration of the formal solution, assuming that the emitting plasma and absorbing plasma are mixed at a constant mass ratio above some minimum radius, below which there is assum...

Parker’s initial insights from 1958 provided a key causal link between the heating of the solar corona and the acceleration of the solar wind. However, we still do not know what fraction of the solar wind’s mass, momentum, and energy flux is driven by Parker-type gas pressure gradients, and what fraction is driven by, e.g., wave-particle interactions or turbulence. SOHO has been pivotal in brin...

In main-sequence stars, at effective temperatures below ' 20 000 K, radiation ceases to be able to drive a stellar wind. In a rather narrow transition regime, elemental segregation seems possible due to the decoupling of He and, under special circumstances, also of H from the absorbing metal ions in the wind. This effect may even be more pronounced, if the wind is surface modulated, say by a ma...

Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physica...

The technique used to control the airflow is based on the electro-hydrodynamic actuator which is also called plasma actuator. This actuator ensures the airflow control thanks to the electric wind created by the electrical corona discharge. This ionic wind is developed at the profile surface tangential to the initial free airflow so that it has a significant effect on the boundary layer flow. Th...

We simulate the effect of latitudinal variations in the location of star spots, as well as their magnetic field strength, on stellar angular momentum loss to the stellar wind. We use the Michigan solar corona global MagnetoHydroDynamic model, which incorporates realistic relation between the magnetic field topology and the wind distribution. We find that the spots’ location significantly affect...