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Related papers: All Coronal Loops are the Same: Evidence to the Co…

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A large part of the hot corona consists of magnetically confined, bright plasma loops. These observed loops are in turn structured into bright strands. We investigate the relationship between magnetic field geometry, plasma properties and…

Solar and Stellar Astrophysics · Physics 2025-12-22 C. A. Breu , D. I. Pontin , E. Priest , I. De Moortel

Context. Slow waves in solar coronal loops are strongly damped. The current theory of damping by thermal conduction cannot explain some observational features.\n Aims. We investigate the propagation of slow waves in a coronal loop built up…

Solar and Stellar Astrophysics · Physics 2024-01-19 Tom Van Doorsselaere , S. Krishna Prasad , Vaibhav Pant , Dipankar Banerjee , Alan Hood

This white paper is a call for a concerted effort to support total solar eclipse observations over the next decade, in particular for the 21 August 2017 eclipse which will traverse the US continent. With the recent advances in image…

Solar and Stellar Astrophysics · Physics 2015-03-19 Shadia R. Habbal , John Cooper , Adrian Daw , Adalbert Ding , Miloslav Druckmuller , Ruth Esser , Judd Johnson , Huw Morgan

The tropical wisdom that when it is hot and dense we can expect rain might also apply to the Sun. Indeed, observations and numerical simulations have shown that strong heating at footpoints of loops, as is the case for active regions, puts…

Solar and Stellar Astrophysics · Physics 2012-02-06 P. Antolin , M. Carlsson , L. Rouppe van der Voort , E. Verwichte , G. Vissers

Decayless kink oscillations of plasma loops in the solar corona may contain an answer to the enigmatic problem of solar and stellar coronal heating. The polarisation of the oscillations gives us a unique information about their excitation…

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal loop-top source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their…

We present spectropolarimetric imaging observations of the solar corona at low frequencies (80 - 240 MHz) using the Murchison Widefield Array (MWA). These images are the first of their kind, and we introduce an algorithm to mitigate an…

Solar and Stellar Astrophysics · Physics 2019-09-04 Patrick I. McCauley , Iver H. Cairns , Stephen M. White , Surajit Mondal , Emil Lenc , John Morgan , Divya Oberoi

Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sanjay Kumar , V. M. Nakariakov , Y. -J. Moon

Using a Monte Carlo ray-tracing code in full general relativity, we calculate the transport of photons from a geodesic hot spot emitter through a corona of hot electrons surrounding a black hole. Each photon is followed until it is either…

Astrophysics · Physics 2007-05-23 Jeremy D. Schnittman

Recent observational and numerical studies show a variety of thermal structures in the solar chromosphere. Given that the thermal interplay across the transition region is a key to coronal heating, it is worth investigating how different…

Solar and Stellar Astrophysics · Physics 2022-10-26 Haruka Washinoue , Munehito Shoda , Takeru K. Suzuki

Context. The solar corona maintains temperatures of a million Kelvin or more. The plasma heating mechanisms responsible for these extreme temperatures are still unclear. Large regions of magnetic activity in the photosphere cause extreme…

Solar and Stellar Astrophysics · Physics 2025-03-17 I. Kraus , Ph. -A. Bourdin , J. Zender , M. Bergmann , A. Hanslmeier

Tomography of the solar corona can provide cruicial constraints for models of the low corona, unique information on changes in coronal structure and rotation rates, and a valuable boundary condition for models of the heliospheric solar…

Instrumentation and Methods for Astrophysics · Physics 2015-09-11 Huw Morgan

The last solar minimum is characterized by several peculiar aspects and by the presence of a complex magnetic topology with two different kinds of coronal streamers: pseudo-streamers and bipolar streamers. Pseudo-streamers or unipolar…

Solar and Stellar Astrophysics · Physics 2015-07-15 Lucia Abbo , Roberto Lionello , Pete Riley , Yi-Ming Wang

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

Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet.…

As the observational signature of the footprints of solar magnetic field lines open into the heliosphere, coronal holes provide a critical measure of the structure and evolution of these lines. Using a combination of Solar and Heliospheric…

Solar and Stellar Astrophysics · Physics 2016-12-23 Chris Lowder , Jiong Qiu , Robert Leamon

Small and elongated, cool and dense blob-like structures are being reported with high resolution telescopes in physically different regions throughout the solar atmosphere. Their detection and the understanding of their formation,…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. Antolin , G. Vissers , L. Rouppe van der Voort

Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed…

Solar and Stellar Astrophysics · Physics 2015-05-14 Steven R. Cranmer

We report spectropolarimetric observations of a supersonic downflow impacting the lower atmosphere within a large sunspot umbra. This work is an extension of Schad et al. 2016 using observations acquired in the He I 10830 Angstrom triplet…

Solar and Stellar Astrophysics · Physics 2021-05-28 Thomas A. Schad , Gabriel I. Dima , Tetsu Anan

A complete understanding of Doppler shift in active region loops can help probe the basic physical mechanism involved into the heating of those loops. Here we present observations of upflows in coronal loops detected in a range of…

Solar and Stellar Astrophysics · Physics 2015-06-05 Durgesh Tripathi , Helen Mason , Giulio Del Zanna , Steven Bradshaw