27 November 2024The presence of “open” magnetic field lines in the solar atmosphere is associated with magnetic flux tubes evolving into solar wind streams subject to the “frozen-in” condition of plasmas. In this study, we statistically test the v - f anticorrelation, exploiting the Solar Orbiter capability to sample a broader range of radial distances compared...

20 November 2024How the outermost layer of the solar atmosphere, namely the solar corona, is maintained to a temperature of more than 1 MK, about 1000 times the photosphere, is an unsolved problem of paramount importance in heliophysics. Observations of impulsive emissions showed that the ones associated with the largest energy scales (from 10^26 to 10^32 erg)...

20 November 2024Zoom into Solar Orbiter's four new Sun images, assembled from high-resolution observations by the spacecraft's PHI and EUI instruments made on 22 March 2023. The PHI images are the highest-resolution full views of the Sun's visible surface to date, including maps of the Sun's messy magnetic field and movement on the surface. These can be...

13 November 2024Energetic ions and electrons accelerated at the Sun can be directly injected into interplanetary space through magnetic “interchange” reconnection between a closed coronal loop and an open magnetic field line. Half a century ago, these transient events, most often associated with impulsive X-ray flares, were observed to produce extreme...

4 November 2024The Sun follows a roughly 11-year rhythm of waking up and becoming very active before calming down again, a stellar beat known as the solar cycle. This affects Earth because it shapes space weather, determining how much radiation, magnetic field and particles the Sun flings out into space and towards our planet.

30 October 2024The Sun is one of the strongest radio sources in the sky producing several kinds of radio emissions differing in characteristics, intensity and mechanism of production. Type III radio bursts are the most common coherent radio emission produced by the Sun. They are characterized by a rapid drift in time towards lower frequencies and represent an...

23 October 2024A crucial step in unraveling the mechanisms behind wave-particle interactions, which drive the heating and acceleration of solar wind particles, lies in the detailed analysis of the non-Maxwellian characteristics of the particle velocity distribution function (VDF). Features such as temperature anisotropies and particle beams offer critical...

26 September 2024Solar wind is a never-ending stream of charged particles coming from the Sun. Rather than a constant breeze, this wind is rather gusty. As solar wind particles travel through space, they interact with the Sun's variable magnetic field, creating chaotic and fluctuating motion known as turbulence.

25 September 2024The acceleration of particles through the explosive release of magnetic energy is a ubiquitous phenomenon in plasmas throughout the Universe. Solar flares provide a unique laboratory for studying these processes. HXRs are considered the smoking guns of flare-accelerated electrons, serving as crucial diagnostic tools. They enable, among others,...

25 September 2024Mesoscale structures are important tracers of solar wind formation because they retain signatures of their heating at their low coronal source, their release, and their acceleration through the high corona. A key observable to investigate the formation of mesoscale structures is the plasma's heavy ion composition and charge states. Solar...