English
Related papers

Related papers: Coronal Heating as Determined by the Solar Flare F…

200 papers

In the context of coronal heating, among the zoo of MHD waves that exist in the solar atmosphere, Alfven waves receive special attention. Indeed, these waves constitute an attractive heating agent due to their ability to carry over the many…

Solar and Stellar Astrophysics · Physics 2014-11-20 P. Antolin , K. Shibata

The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still today, the wind…

Solar and Stellar Astrophysics · Physics 2016-05-17 Lauren N. Woolsey

The content of coronal material in the quiet Sun is not constant as soft X-ray and high-temperature EUV line observations have shown. New material, probably heated and evaporated from the chromosphere is occasionally injected even in the…

Astrophysics · Physics 2007-05-23 Arnold O. Benz , Sam Krucker

In the solar atmosphere, Alfv\'en waves are believed to play an important role in the transfer of energy from the photosphere to the corona and solar wind, and in the heating of the chromosphere. We perform numerical computations to…

Solar and Stellar Astrophysics · Physics 2019-01-23 Roberto Soler , Jaume Terradas , Ramon Oliver , Jose Luis Ballester

The Sun's corona, heated to temperatures exceeding one million Kelvin despite lying above the cooler photosphere, has puzzled astrophysicists since its discovery in the 1940s. Prevailing theories, based on acoustic and magnetohydrodynamic…

Solar and Stellar Astrophysics · Physics 2025-03-18 Anil Narayan Raghav

The solar coronal heating problem is an open question since 1939. One proposed model for the transport and release of mechanical energy generated in the sub-phorospheric layers and photosphere is the nanoflare model that incorporates Ohmic…

Solar and Stellar Astrophysics · Physics 2017-07-12 Charalambos Kanella , Boris V. Gudiksen

The optical and near-ultraviolet (NUV) continuum radiation in M dwarf flares is thought to be the impulsive response of the lower stellar atmosphere to magnetic energy release and electron acceleration at coronal altitudes. This radiation…

Solar and Stellar Astrophysics · Physics 2023-02-07 Adam F. Kowalski

Coronal waves, significant solar phenomena, act as diagnostic tools for scientists studying solar atmosphere properties. Here, we present a novel observation detailing how a coronal wave event, associated with an X5.0 class flare,…

The solar corona is a template to understand stellar activity. The Sun is a moderately active star, and its corona differs from active stars: active stellar coronae have a double-peaked EM(T) with the hot peak at 8-20 MK, while the non…

Astrophysics · Physics 2009-11-13 C. Argiroffi , G. Peres , S. Orlando , F. Reale

Nanoflares are believed to be key contributors to heating solar non-flaring active regions, though their individual detection remains challenging. This study uses a data-driven field-aligned hydrodynamic model to examine nanoflare…

Solar and Stellar Astrophysics · Physics 2024-12-31 Biswajit Mondal , James A Klimchuk , Amy R. Winebarger , P. S. Athiray , Jiayi Liu

Parker (1983) suggested a mechanism for the formation of current sheets (CSs) in the solar atmosphere. His main idea was that the tangling of coronal magnetic field lines by photospheric random flows facilitates the continuous formation of…

Solar and Stellar Astrophysics · Physics 2021-08-05 Loukas Vlahos , Heinz Isliker , Nikos Sioulas

Context. We investigate the statistics of the spatial and temporal distribution of the coronal heating in a three-dimensional magneto- hydrodynamical (3D MHD) model. The model describes the temporal evolution of the corona above an observed…

Solar and Stellar Astrophysics · Physics 2015-06-12 Sven Bingert , Hardi Peter

It is largely agreed that many coronal loops---those observed at a temperature of about 1 MK--- are bundles of unresolved strands that are heated by storms of impulsive nanoflares. The nature of coronal heating in hotter loops and in the…

Solar and Stellar Astrophysics · Physics 2015-05-28 Nicholeen M. Viall , James A. Klimchuk

The dynamical response of the solar corona to surface and sub-surface perturbations depends on the chromospheric stratification, and specifically on how efficiently these layers reflect or transmit incoming Alfv\'en waves. While it would be…

Solar and Stellar Astrophysics · Physics 2015-06-12 R. F. Pinto , R. Grappin , M. Velli , A. Verdini

We investigate the contribution of very weak flares to the coronal luminosity of low-mass active stars. We analyze EUVE/DS events data from FK Aqr, V1054 Oph, and AD Leo and conclude that in all these cases the coronal emission is dominated…

Astrophysics · Physics 2009-11-07 Vinay Kashyap , Jeremy Drake , Manuel Guedel , Marc Audard

Observational measurements of active region emission measures contain clues to the time-dependence of the underlying heating mechanism. A strongly non-linear scaling of the emission measure with temperature indicates a large amount of hot…

Solar and Stellar Astrophysics · Physics 2015-06-11 Stephen J. Bradshaw , James A. Klimchuk , Jeffrey W. Reep

Although the mechanisms responsible for heating the Sun's corona and accelerating the solar wind are still being actively investigated, it is largely accepted that photospheric motions provide the energy source and that the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-18 Roberto Lionello , Marco Velli , Cooper Downs , Jon A. Linker , Zoran Mikić , Andrea Verdini

Context. It is known that Alfv\'en and magnetoacoustic waves both contribute to the heating of the solar chromosphere and drive plasma outflows. In both cases, the thermalization of the wave energy occurs due to ion-neutral collisions, but…

Solar and Stellar Astrophysics · Physics 2022-11-24 M. Pelekhata , K. Murawski , S. Poedts

The heating of solar coronal loops is at the center of the problem of coronal heating. Given that the origin of the fast solar wind has been tracked down to atmospheric layers with transition region or even chromospheric temperatures, it is…

Solar and Stellar Astrophysics · Physics 2014-06-05 Bo Li , Haixia Xie , Xing Li , Li-Dong Xia

Nanoflares have been proposed as the main source of heating of the solar corona. However, detecting them directly has so far proved elusive, and extrapolating to them from the properties of larger brightenings gives unreliable estimates of…

Astrophysics · Physics 2009-11-11 Anuschka Pauluhn , Sami K. Solanki