Extreme-ultraviolet late phase (ELP) refers to the second extreme-ultraviolet (EUV) radiation enhancement observed in certain solar flares, which usually occurs tens of minutes several hours after peak soft X-ray emission. The coronal loop system that hosts ELP emission is often different from main flaring arcade, and enhanced EUV therein may imply an additional heating process. However, origin...

Abstract Waiting-time distributions of solar flares and coronal mass ejections (CMEs) exhibit power-law-like distribution functions with slopes in the range α τ ≈ 1.4–3.2, as observed annual data sets during four cycles (1974–2012). We find a close correlation between waiting-time power-law slope sunspot number (SN), i.e., = 1.38 + 0.01 × SN. The can be fitted Pareto-type function form N ( ) 0 ...

ABSTRACT The modulation of the intensity microwave emission from a plasma slab caused by standing linear kink fast magnetoacoustic wave is considered. stretched along straight magnetic field, and can represent, for example, current sheet in flaring active region corona Sun, or streamer pseudostreamer stalk. density non-uniform perpendicular direction described symmetric Epstein profile. paramet...

We analyse the coronal elemental abundances during a small flare using Hinode/EIS observations. Compared to pre-flare abundances, we observed strong increase in abundance of Ca XIV 193.84 {\AA}, an emission line with low first ionisation potential (FIP < 10 eV), as quantified by ratio Ca/Ar flare. This is contrast unchanged Si X 258.38 {\AA}/S 264.23 {\AA}. propose two different mechanisms expl...

Interfaces between spindle microtubules and kinetochores were examined in diverse species by electron tomography and image analysis. Overall structures were conserved in a mammal, an alga, a nematode, and two kinds of yeasts; all lacked dense outer plates, and most kinetochore microtubule ends flared into curved protofilaments that were connected to chromatin by slender fibrils. Analyses of cur...

We propose a new model for quasi-periodic modulation of solar and stellar flaring emission. Fast magnetoacoustic oscillations of a non-flaring loop can interact with a nearby flaring active region. This interaction occurs when part of the oscillation situated outside the loop reaches the regions of steep gradients in magnetic field within an active region and produces periodic variations of ele...

We investigate the possibility of an electron cyclotron maser operating in a hot (T > 107K) thermal plasma with a loss cone. We find that the instability can occur in this scenario because resonance involving electrons in the thermal tail can give rise to significantly large growth rates. We estimate the range of electron velocities that can be in resonance and show how this dictates the freque...

Context. The Solar First Ionization Potential (FIP) effect, where low-FIP (FIP <∼10 eV) elements are enriched in the corona relative to the photosphere, while high-FIP abundances remain unchanged, has been known for a long while. High resolution X-ray spectroscopy has revealed that active stellar coronae show an opposite effect, which was labeled the Inverse-FIP (IFIP) effect. The correlation f...