Related papers: Solar extreme events
Observations of the Sun and of Sun-like stars provide access to different aspects of stellar magnetic activity that, when combined, help us piece together a more comprehensive picture than can be achieved from only the solar or the stellar…
Solar flares and coronal mass ejections (CMEs) are among the most energetic phenomena in the solar system, often impacting space weather and terrestrial technologies. In this study, we utilize SunPy, an open-source Python library for solar…
Recent irradiance measurements from numerous heliophysics and astrophysics missions including SDO, GOES, Kepler, TESS, Chandra, XMM-Newton, and NICER have provided critical input in understanding the physics of the most powerful transient…
It is generally accepted that extreme space weather events tend to be related to strong flares and fast halo coronal mass ejections CMEs. In the present paper, we carefully identify the chain of events from the Sun to the Earth induced by…
We report results from a five-year (132-night) dedicated observational campaign targeting two nearby young solar-type stars, EK Draconis ($\sim$50-125 Myr age) and V889 Hercules ($\sim$30 Myr age), using the 3.8m Seimei Telescope and…
The Kepler mission identified huge flares on various stars including some of solar type. These events are substantially more energetic than solar flares, and so they are referred to as superflares. Even a small probability of such a…
Solar eruptive events, including solar flares and coronal mass ejections (CMEs), are typically characterised by energetically significant X-ray emissions from flare-accelerated electrons and hot thermal plasmas. Occulted events, where the…
The earliest evidence on spatial distributions of solar energetic particles (SEPs) compared events from many different source longitudes on the Sun, but the early Pioneers provided the first evidence of the large areas of equal SEP…
Coronal Mass Ejections (CMEs) may have major importance for planetary and stellar evolution. Stellar CME parameters, such as mass and velocity, have yet not been determined statistically. So far only a handful of stellar CMEs has been…
Impulsive solar energetic-particle (SEP) events were first distinguished as the streaming electrons that produce type III radio bursts as distinct from shock-induced type II bursts. They were then observed as the surprisingly-enhanced…
Gradual solar energetic particle (SEP) events, usually attributed to shock waves driven by coronal mass ejections (CMEs), show a wide variety of temporal behaviors. For example, TO, the >10 MeV proton onset time with respect to the launch…
The solar soft X-ray observations from the GOES satellites provide one of the best quantitative records of solar activity, with nearly continuous flare records since 1975. We present a uniform analysis of the entire time series for 1975 to…
The PAMELA satellite experiment is providing first direct measurements of Solar Energetic Particles (SEPs) with energies from about 80 MeV to several GeV in near-Earth space, bridging the low energy data by other space-based instruments and…
Active region 11029 was a small, highly flare-productive solar active region observed at a time of extremely low solar activity. The region produced only small flares: the largest of the $>70$ Geostationary Observational Environmental…
The Sun offers a convenient nearby laboratory to study the physical processes of particle acceleration and impulsive energy release in magnetized plasmas that occur throughout the universe, from planetary magnetospheres to black hole…
Flares are powerful events ignited by a sudden release of magnetic energy. With the aim of studying flares in the 125-Myr-old stars in the Pleiades observed simultaneously in optical and X-ray light, we obtained new XMM-Newton observations…
Flares and CMEs are very powerful events in which energetic radiation and particles are ejected within a short time. These events thus can strongly affect planets that orbit these stars. This is particularly relevant for planets of M-stars,…
Solar flares are a fundamental component of solar eruptive events (SEEs; along with solar energetic particles, SEPs, and coronal mass ejections, CMEs). Flares are the first component of the SEE to impact our atmosphere, which can set the…
Large solar energetic particle (SEP) events are thought to originate from the shocks driven by fast coronal mass ejections (CMEs) and thus generally accompanied by type II radio bursts. However, a significant proportion of type II radio…
Two scenarios have been proposed to account for sustained $\ge 30$\,MeV gamma-ray emission in solar flares: (1) prolonged particle acceleration/trapping involving large-scale magnetic loops at the flare site, and (2) precipitation of…