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Related papers: Deciphering the solar coronal heating: Energizing …

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Decayless kink oscillations of solar coronal loops (or decayless oscillations for short) have attracted great attention since their discovery. Coronal bright points (CBPs) are mini-active regions and consist of loops with a small size.…

Solar and Stellar Astrophysics · Physics 2022-05-18 Yuhang Gao , Hui Tian , Tom Van Doorsselaere , Yajie Chen

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…

{Chromospheric evaporation is a key process in solar flares that has extensively been investigated using the spectroscopic observations. However, direct soft X-ray (SXR) imaging of the process is rare, especially in remote brightenings…

Solar and Stellar Astrophysics · Physics 2015-06-16 Q. M. Zhang , H. S. Ji

Coronal loops are the basic building block of the upper solar atmosphere. Comprehending how these are energized, structured, and evolve is key to understanding stellar coronae. Here we investigate how the energy to heat the loop is…

Solar and Stellar Astrophysics · Physics 2022-02-09 C. Breu , H. Peter , R. Cameron , S. K. Solanki , D. Przybylski , M. Rempel , L. P. Chitta

Small (400 to 4000 km) and short lived (10 to 200 km) extreme ultraviolet (EUV) brightenings, detected by the High Resolution Imager EUV (HRIEUV), have been found to be ubiquitous in the Quiet Sun (QS). Their contribution to coronal heating…

Solar and Stellar Astrophysics · Physics 2025-07-02 A. Dolliou , J. A. Klimchuk , S. Parenti , K. Bocchialini

What physical mechanisms heat the outer solar or stellar atmosphere to million-Kelvin temperatures is a fundamental but long-standing open question. In particular, the solar corona in active region cores contains an even hotter component…

Solar and Stellar Astrophysics · Physics 2024-04-09 Zekun Lu , Feng Chen , M. D. Ding , Can Wang , Yu Dai , Xin Cheng

Condensations in the more than 10^6 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide…

Solar and Stellar Astrophysics · Physics 2012-09-06 H. Peter , S. Bingert , S. Kamio

Despite decades of studying the Sun, the coronal heating problem remains unsolved. One fundamental issue is that we do not know the spatial scale of the coronal heating mechanism. At a spatial resolution of 1000 km or more it is likely that…

Solar and Stellar Astrophysics · Physics 2012-06-07 David H. Brooks , Harry P. Warren , Ignacio Ugarte-Urra

Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned…

Solar and Stellar Astrophysics · Physics 2012-08-14 R. B. Dahlburg , G. Einaudi , A. F. Rappazzo , M. Velli

How magnetic energy is injected and released in the solar corona, keeping it heated to several million degrees, remains elusive. Coronal heating generally increases with increasing magnetic field strength. From comparison of a non-linear…

Solar and Stellar Astrophysics · Physics 2017-07-19 Sanjiv K. Tiwari , Julia K. Thalmann , Navdeep K. Panesar , Ronald L. Moore , Amy R. Winebarger

Coronal bright points (CBPs) and jets are ubiquitous small-scale brightenings that are often associated with each other. In this paper, we report our multiwavelength observations of two groups of homologous jets. The first group was…

Solar and Stellar Astrophysics · Physics 2016-04-13 Q. M. Zhang , H. S. Ji , Y. N. Su

Our aim is to investigate the intensity oscillations in coronal X-ray Bright Points (XBPs). We analysed a 7-hours long time sequence of the soft X-ray images obtained on April 14, 2007 with 2-min cadence using X-Ray Telescope (XRT) on-board…

Astrophysics · Physics 2015-05-13 R. Kariyappa , B. A. Varghese

Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic…

Solar and Stellar Astrophysics · Physics 2025-06-24 Gregory D. Fleishman , Alexey A. Kuznetsov , Gelu M. Nita

Observing the Sun at high time and spatial scales is a step towards understanding the finest and fundamental scales of heating events in the solar corona. The Hi-C instrument has provided the highest spatial and temporal resolution images…

Evidence for small amounts of very hot plasma has been found in active regions and might be the indication of an impulsive heating, released at spatial scales smaller than the cross section of a single loop. We investigate the heating and…

Solar and Stellar Astrophysics · Physics 2016-01-13 E. Tajfirouze , F. Reale , A. Petralia , P. Testa

The heating of the solar chromosphere and corona to the observed high temperatures, imply the presence of ongoing heating that balances the strong radiative and thermal conduction losses expected in the solar atmosphere. It has been…

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

One scenario proposed to explain the million degrees solar corona is a finely-stranded corona where each strand is heated by a rapid pulse. However, such fine structure has neither been resolved through direct imaging observations nor…

Solar and Stellar Astrophysics · Physics 2015-05-28 Fabio Reale , Massimiliano Guarrasi , Paola Testa , Edward E. DeLuca , Giovanni Peres , Leon Golub

The inference of the magnetic field vector from spectropolarimetric observations is crucial for understanding the physical processes governing the solar corona. We investigate which information on the magnetic fields of coronal bright…

Solar and Stellar Astrophysics · Physics 2025-08-27 Ernest Alsina Ballester , Daniel Nóbrega-Siverio , Fernando Moreno-Insertis , Supriya Hebbur Dayananda

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…

Solar and Stellar Astrophysics · Physics 2014-05-08 F. Chen , H. Peter , S. Bingert , M. C. M. Cheung