English
Related papers

Related papers: A comparison of the active region upflow and core …

200 papers

Three homologous C-class flares and one last M-class flare were observed by both the Solar Dynamics Observatory (SDO) and the Hinode EUV Imaging Spectrometer (EIS) in the AR 11429 on March 9, 2012. All the recurrent flares occurred within a…

Solar and Stellar Astrophysics · Physics 2017-04-26 V. Polito , G. Del Zanna , G. Valori , E. Pariat , H. E. Mason , J. Dudik , M. Janvier

Accurate forecasting of space weather requires knowledge of the source regions where solar energetic particles (SEP) and eruptive events originate. Recent work has linked several major SEP events in 2014, January, to specific features in…

Solar and Stellar Astrophysics · Physics 2021-09-24 David H. Brooks , Stephanie L. Yardley

Strong solar flares and coronal mass ejections, here defined not only as the bursts of electromagnetic radiation but as the entire process in which magnetic energy is released through magnetic reconnection and plasma instability, emanate…

Solar and Stellar Astrophysics · Physics 2019-05-29 Shin Toriumi , Haimin Wang

The exploration of the inner heliosphere by Parker Solar Probe has revealed a highly structured solar wind with ubiquitous deflections from the Parker spiral, known as switchbacks. Interchange reconnection (IR) may play an important role in…

The determination of solar wind outflow velocity is fundamental in order to probe the mechanisms of wind acceleration in the corona. We aim to study, via the Doppler dimming technique, the effects that the chromospheric Ly{\alpha} line…

The Sun features on its surface typical flow patterns called the granulation, mesogranulation, and supergranulation. These patterns arise due to convective flows transporting energy from the interior of the Sun to its surface. In this paper…

Solar and Stellar Astrophysics · Physics 2019-02-20 J. I. Campos Rozo , D. Utz , S. Vargas Dominguez , A. Veronig , T. Van Doorsselaere

We investigate the plasma dynamics (outflow speed and turbulence) inside polar plumes. We compare line profiles (mainly of \ion{O}{6}) observed by the UVCS instrument on SOHO at the minimum of solar cycle 22-23 with model calculations. We…

Astrophysics · Physics 2010-11-11 N. -E. Raouafi , J. W. Harvey , S. K. Solanki

Waves have long been thought to contribute to the heating of the solar corona and the generation of the solar wind. Recent observations have demonstrated evidence of quasi-periodic longitudinal disturbances and ubiquitous transverse wave…

Solar and Stellar Astrophysics · Physics 2015-06-16 J. Threlfall , I. De Moortel , S. W. McIntosh , C. Bethge

Although the solar wind flows primarily outward from the Sun to interplanetary space, there are times when small-scale plasma inflows are observed. Inward-propagating density fluctuations in polar coronal holes were detected by the COR2…

Solar and Stellar Astrophysics · Physics 2021-05-26 Steven R. Cranmer , Craig E. DeForest , Sarah E. Gibson

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

Context: Flux emergence in the solar atmosphere is a complex process that causes a release of magnetic energy as heat and acceleration of solar plasma at a variety of spatial scales. Methods: We analysed imaging spectropolarimetric data…

We study the effect of newly emerged solar active regions (ARs) on the large-scale magnetic environment of pre-existing ARs (PEARs). We first present a theoretical approach to quantify the "interaction energy" between new ARs and PEARs as…

Solar and Stellar Astrophysics · Physics 2016-06-09 Yixing Fu , Brian T. Welsch

Ubiquitous small-scale vortices have recently been found in the lower atmosphere of the quiet Sun in state-of-the-art solar observations and in numerical simulations. We investigate the characteristics and temporal evolution of a…

Solar and Stellar Astrophysics · Physics 2016-01-27 S. -H. Park , G. Tsiropoula , I. Kontogiannis , K. Tziotziou , E. Scullion , J. G. Doyle

Certain solar flares exhibit a distinctive candle-flame or cusp-shaped feature above the bright flare arcade visible in extreme ultraviolet (EUV) and X-ray channels sensitive to high-temperature plasma. The presence of a cusp-like structure…

Solar and Stellar Astrophysics · Physics 2026-05-19 Ivan Oparin , Sabastian Fernandes , Bin Chen , Chengcai Shen , Xiaocan Li , Fan Guo , Sijie Yu

The processes of the coronal plasma heating and cooling were previously shown to significantly affect the dynamics of slow magnetoacoustic (MA) waves, causing amplification or attenuation, and also dispersion. However, the entropy mode is…

Solar and Stellar Astrophysics · Physics 2021-06-23 D. I. Zavershinskii , D. Y. Kolotkov , D. S. Riashchikov , N. E. Molevich

Solar flares are widely accepted to be powered by magnetic reconnection that involves complex dynamics in various scales. The flare supra-arcade and loop-top region, directly impacted by fast reconnection downflows, contains a wealth of…

Solar and Stellar Astrophysics · Physics 2025-05-27 Tingyu Gou , Katharine K. Reeves

We examine the hypothesis that plasma associated with "Type II" spicules is heated to coronal temperatures, and that the upward moving hot plasma constitutes a significant mass supply to the solar corona. 1D hydrodynamical models including…

Solar and Stellar Astrophysics · Physics 2015-06-03 Philip G. Judge , Bart de Pontieu , Scott McIntosh , Kosovare Olluri

We report on new spectro-polarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at…

Within the coronae of stars, abundances of those elements with low first ionization potential (FIP) often differ from their photospheric values. The coronae of the Sun and solar-type stars mostly show enhancements of low-FIP elements (the…

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal…

Solar and Stellar Astrophysics · Physics 2017-10-11 Steven R. Cranmer , Sarah E. Gibson , Pete Riley