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Related papers: Nanoflare Activity in the Solar Chromosphere

200 papers

It has been suggested that the hot plasma of the solar corona comes primarily from impulsive heating events, or nanoflares, that occur in the lower atmosphere, either in the upper part of the ordinary chromosphere or at the tips of type II…

Solar and Stellar Astrophysics · Physics 2015-06-19 J. A. Klimchuk , S. J. Bradshaw

Coronal heating through the explosive release of magnetic energy remains an open problem in solar physics. Recent hydrodynamical models attempt an investigation by placing swarms of 'nanoflares' at random sites and times in modeled…

Solar and Stellar Astrophysics · Physics 2016-11-30 K. Moraitis , A. Toutountzi , H. Isliker , M. Georgoulis , L. Vlahos , G. Chintzoglou

Magnetic energy is required to heat the corona, the outer atmosphere of the Sun, to millions of degrees. We study the nature of the magnetic energy source that is probably responsible for the brightening of coronal loops driven by…

Solar and Stellar Astrophysics · Physics 2018-07-25 L. P. Chitta , H. Peter , S. K. Solanki

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

EUV observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared to…

Solar and Stellar Astrophysics · Physics 2011-02-11 S. Patsourakos , J. A. Klimchuk

X-ray observations of the Sun led Eugene Parker to propose nanoflares as the basic energy-release units that heat the solar corona. Decades later, Solar Orbiter's Extreme Ultraviolet Imager (HRIEUV), operating halfway between Earth and the…

Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…

Solar and Stellar Astrophysics · Physics 2025-07-25 Gottfried Mann , Frédéric Schuller

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

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

Small-scale impulsive events, known as nanoflares, are thought to be one of the prime candidates that can keep the solar corona hot at its multi-million Kelvin temperature. Individual nanoflares are difficult to detect with the current…

Nanoflares are thought to be one of the prime candidates that can heat the solar corona to its multi-million kelvin temperature. Individual nanoflares are difficult to detect with the present generation instruments, however their presence…

This letter explores the relevance of nanoflare based models for heating the quiet sun corona. Using metrewave data from the Murchison Widefield Array, we present the first successful detection of impulsive emissions down to flux densities…

Solar and Stellar Astrophysics · Physics 2021-02-25 Surajit Mondal , Divya Oberoi , Atul Mohan

This review surveys the statistics of solar X-ray flares, emphasising the new views that RHESSI has given us of the weaker events (the microflares). The new data reveal that these microflares strongly resemble more energetic events in most…

Solar and Stellar Astrophysics · Physics 2011-09-01 I. G. Hannah , H. S. Hudson , M. Battaglia , S. Christe , J. Kasparova , S. Krucker , M. R. Kundu , A. Veronig

Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot…

Solar and Stellar Astrophysics · Physics 2011-02-11 Fabio Reale , Paola Testa , James A. Klimchuk , Susanna Parenti

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established.…

Solar and Stellar Astrophysics · Physics 2025-02-05 Louis-Simon Guité , Antoine Strugarek , Paul Charbonneau

Much evidence suggests that the solar corona is heated impulsively, meaning that nanoflares may be ubiquitous in quiet and active regions (ARs). Hard X-ray (HXR) observations with unprecedented sensitivity $>$3~keV are now enabled by…

We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale…

Astrophysics · Physics 2009-10-30 Pablo Dmitruk , Daniel O. Gomez

We present a detailed analysis of a 3D MHD simulation of a subset of the magnetic flux in an active region. The simulation models the generation of nanoflares and response of the plasma to imposed photospheric motions. Our study focuses on…

Solar and Stellar Astrophysics · Physics 2025-09-26 Shanwlee Sow Mondal , Lars K. S. Daldorff , James A. Klimchuk , Craig D. Johnston

The solar corona has been revealed in the past decade to be a highly dynamic nonequilibrium plasma environment. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be strongly turbulent, but…

Astrophysics · Physics 2008-11-26 Steven R. Cranmer

This paper is an attempt to understand the physical processes occurring in different layers of solar atmosphere during a solar flare. For a complete understanding of the flare we must analyze multi-wavelength datasets, as emission at…

Solar and Stellar Astrophysics · Physics 2020-09-30 Shirsh Lata Soni , Radhe Shyam Gupta , Adya Prasad Mishra