Related papers: Solar off-limb line widths: Alfven waves, ion-cycl…

EUV images of Comet Lovejoy (C/2011 W3) from the AIA show striations related to the magnetic field structure in both open and closed magnetic regions. The brightness contrast implies coronal density contrasts of at least a factor of 6…

There have been several ideas proposed to explain how the Sun's corona is heated and how the solar wind is accelerated. Some models assume that open magnetic field lines are heated by Alfven waves driven by photospheric motions and…

In the corona, plasma is accelerated to hundreds of kilometers per second, and heated to temperatures hundreds of times hotter than the Sun's surface, before it escapes to form the solar wind. Decades of space-based experiments have shown…

The problem of explaining observed soft X-ray fluxes during solar flares, which invokes acceleration of large fraction of electrons, if the acceleration takes places at the solar coronal loop-top, can potentially be solved by postulating…

Flare ribbons are bright manifestations of flare energy dissipation in the lower solar atmosphere. For the first time, we report on high-resolution imaging spectroscopy observations of flare ribbons situated off-limb in the H$\beta$ and Ca…

Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-turbulence spectrum and ultimately heating/accelerating the…

Context. We address the heating of the solar chromosphere and the related generation of plasma inflows and outflows. Aims. We attempt to detect variations in ion temperature and vertical plasma flows, which are driven by impulsively excited…

We investigate the properties and relationship between Doppler-velocity fluctuations and intensity fluctuations in the off-limb quiet Sun corona. These are expected to reflect the properties of Alfvenic and compressive waves, respectively.…

We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \Alfven (fast MHD) waves…

Magneto-hydrodynamic (MHD) Alfv\'en waves have been a focus of laboratory plasma physics and astrophysics for over half a century. Their unique nature makes them ideal energy transporters, and while the solar atmosphere provides…

The heating of magnetized plasma by propagation of Alfven waves is calculated as a function of the magnetic field spectral density. The results can be applied to evaluate the heating power of the solar corona at known data from satellites'…

The heating of coronal loops is investigated to understand the observational consequences in terms of the thermodynamics and radiative losses from the Sun as well as the magnetized coronae of stars with an outer convective envelope. The…

We present a comprehensive model of the global properties of Alfven waves in the solar atmosphere and fast solar wind. Linear non-WKB wave transport equations are solved from the photosphere to 4 AU, and for wave periods ranging from 3…

M dwarf's atmosphere and wind is expected to be highly magnetized. The nonlinear propagation of Alfv\'en wave could play a key role in both heating the stellar atmosphere and driving the stellar wind. Along this Alfv\'en wave scenario, we…

The solar wind is the extension of the Sun's hot and ionized corona, and it exists in a state of continuous expansion into interplanetary space. The radial distance at which the wind's outflow speed exceeds the phase speed of Alfvenic and…

Quiescent streamers are characterized by a peculiar UV signature as pointed out by the results from the observations of the Ultraviolet and Coronograph Spectrometer (UVCS) on board SOHO: the intensity of heavy ion emission lines (such as…

The measured spectrum of kinetic Alfven wave fluctuations in the turbulent solar wind plasma is used to calculate the electron and ion distribution functions resulting from quasi-linear diffusion. The modified ion distribution function is…

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude…

The effect of the electron density stratification on the intensity profiles of the H I Ly-$\alpha$ line and the O VI and Mg X doublets formed in solar coronal holes is investigated. We employ an analytical 2-D model of the large scale…

Eclipses are very favourable for the photosphere- chromosphere and corona interface observation as the occultation takes place in space, free of parasitic light coming from the occulting disk (the Moon). Independently, EUV filtergrams of…