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Related papers: Long-lived coronal loops in solar active regions

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Coronal rain is the most dramatic cooling phenomenon of the solar corona and an essential diagnostic tool for the coronal heating properties. A puzzling feature of the solar corona, besides the heating, is its EUV filamentary structure and…

We report for the first time the detection of thermal free-free emission from post-flare loops at 34GHz in images from the Nobeyama Radioheliograph (NoRH). We studied 8 loops, 7 of which were from regions with extremely strong coronal…

Solar and Stellar Astrophysics · Physics 2024-06-24 Costas E. Alissandrakis , Gregory D. Fleishman , Viktor V. Fedenev , Stephen M. White , Alexander T. Altyntsev

The Enthalpy Based Thermal Evolution of Loops (EBTEL) approximate model for static and dynamic coronal loops is developed to include the effect of a loop cross-sectional area which increases from the base of the transition region (TR) to…

Solar and Stellar Astrophysics · Physics 2021-11-19 P. J. Cargill , S. J. Bradshaw , J. A. Klimchuk , W. T. Barnes

Data from recent numerical simulations of the solar corona and transition region are analysed and the magnetic field connection between the low corona and the photosphere is found to be close to that of a potential field. The fieldline to…

Astrophysics · Physics 2014-10-13 B. V. Gudiksen , Å. Nordlund

We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by…

Solar and Stellar Astrophysics · Physics 2016-10-12 F. Reale , S. Orlando , M. Guarrasi , A. Mignone , G. Peres , A. W. Hood , E. R. Priest

It was once thought that all coronal loops are in static equilibrium, but observational and modeling developments over the past decade have shown that this is clearly not the case. It is now established that warm (~1 MK) loops observed in…

Solar and Stellar Astrophysics · Physics 2009-04-09 James A. Klimchuk

In addition to a component of the emission that originates from clearly distinguishable coronal loops, the solar corona also exhibits extreme-ultraviolet (EUV) and X-ray ambient emission that is rather diffuse and is often considered…

Solar and Stellar Astrophysics · Physics 2023-03-24 Nikolina Milanović , Lakshmi Pradeep Chitta , Hardi Peter

Coronal loops are fundamental building blocks of the solar active regions and the corona. Therefore, a clear understanding of the physics of coronal loops will help us understand the physics of active region heating in particular and…

Solar and Stellar Astrophysics · Physics 2011-02-11 D. Tripathi , H. E. Mason , B. N. Dwivedi , G. Del Zanna , P. R. Young

The magnetic field in the Sun's corona stores energy that can be released to heat the coronal plasma and drive solar eruptions. Measurements of the global coronal magnetic field have been limited to a few snapshots. We present observations…

Solar and Stellar Astrophysics · Physics 2024-10-23 Zihao Yang , Hui Tian , Steven Tomczyk , Xianyu Liu , Sarah Gibson , Richard J. Morton , Cooper Downs

Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically…

Solar and Stellar Astrophysics · Physics 2023-11-03 I. Kraus , Ph. -A. Bourdin , J. Zender , M. Bergmann , A. Hanslmeier

Extracting the temperature of coronal loops is effective in the analysis of solar active region's loops and helps in better understanding of coronal events. To this end, various methods have already been developed like the method developed…

Solar and Stellar Astrophysics · Physics 2019-08-30 Narges Fathalian

We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…

Solar and Stellar Astrophysics · Physics 2017-12-05 Jörn Warnecke , Feng Chen , Sven Bingert , Hardi Peter

We present here one of the first high resolution spectroscopic observations of coronal rain, performed with the CRISP instrument at the Swedish Solar Telescope. This work constitutes the first attempt to assess the importance of coronal…

Solar and Stellar Astrophysics · Physics 2015-06-03 Patrick Antolin , Luc Rouppe van der Voort

At low coronal temperatures around or below 1 MK distinct areas in the surroundings of active regions (AR) show emission at a level significantly below the emission coming from the quiet Sun (QS). These areas are referred to as dark halos,…

Solar and Stellar Astrophysics · Physics 2026-05-13 J. D. Nölke , S. K. Solanki , J. Hirzberger , H. Peter , L. P. Chitta , K. H. Glassmeier , D. Calchetti , G. Valori

Coronal loops are basic building blocks of solar atmosphere and are observed on various length scales. However, their formation mechanism is still unclear. In this paper, we present the spectroscopic and imaging observations of small-scale…

Solar and Stellar Astrophysics · Physics 2022-04-06 Girjesh R. Gupta , Sushree S. Nayak

This work addresses the problem of plasma condensation and ``catastrophic cooling'' in solar coronal loops. We have carried out numerical calculations of coronal loops and find several classes of time-dependent solutions (static, periodic,…

Astrophysics · Physics 2009-11-10 D. A. N. Mueller , H. Peter , V. H. Hansteen

We use time series observations from the SOHO and Yohkoh spacecraft to study solar polar rays. Contrary to our expectations, we find that the rays are associated with active regions on the sun and are not features of the polar coronal…

Astrophysics · Physics 2009-10-31 Jing Li , David Jewitt , Barry LaBonte

The \textit{Sun Watcher using Active Pixel system detector and Image Processing}(SWAP) on board the \textit{PRoject for OnBoard Autonomy\todash 2} (PROBA\todash 2) spacecraft provides images of the solar corona in EUV channel centered at…

Solar and Stellar Astrophysics · Physics 2012-06-11 K. Chandrashekhar , S. Krishna Prasad , D. Banerjee , B. Ravindra , Daniel B. Seaton

The opening-up of the magnetic field during solar eruptive events is often accompanied by a dimming of the local coronal emission. From observations of filament eruptions recorded with the Extreme-Ultraviolet Imager on STEREO during…

Solar and Stellar Astrophysics · Physics 2011-03-10 Eva Robbrecht , Yi-Ming Wang

Context. The details of the spectral profiles of extreme UV emission lines from solar active regions contain key information to investigate the structure, dynamics, and energetics of the solar upper atmosphere. Aims. We characterize the…

Solar and Stellar Astrophysics · Physics 2019-06-19 Leping Li , Hardi Peter
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