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Related papers: EIT waves and coronal magnetic field diagnostics

200 papers

Here we report on the unique observation of flaring coronal loops at the solar limb using high resolution imaging spectropolarimetry from the Swedish 1-meter Solar Telescope. The vantage position, orientation and nature of the chromospheric…

Magnetic field diagnostics of the transition region from the chromosphere to the corona faces us with the problem that one has to apply extreme UV spectro-polarimetry. While for coronal diagnostic techniques already exist through infrared…

Solar and Stellar Astrophysics · Physics 2013-03-11 H. Peter

The origin of the Moreton wave observed in the chromosphere and the EIT wave observed in the corona during the eruption remains being an active research subject for a while. We investigate numerically in this work the evolutionary features…

Solar and Stellar Astrophysics · Physics 2009-07-24 Hongjuan Wang , Chengcai Shen , Jun Lin

The large field-of-view of the Sun Watcher using Active Pixel System detector and Image Processing (SWAP) instrument on board the PRoject for Onboard Autonomy 2 (PROBA2) spacecraft provides a unique opportunity to study extended coronal…

Solar and Stellar Astrophysics · Physics 2020-08-05 Karen A. Meyer , Duncan H. Mackay , Dana-Camelia Talpeanu , Lisa A. Upton , Matthew J. West

Context. The observation of >100 MeV {\gamma}-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions…

Solar and Stellar Astrophysics · Physics 2017-12-27 I. Plotnikov , A. P. Rouillard , G. H. Share

The only way to obtain reliable empirical information on the intensity and topology of the weak magnetic fields of the quiet solar chromosphere is via the measurement and rigorous physical interpretation of polarization signals in…

Astrophysics · Physics 2011-04-12 J. Trujillo Bueno , R. Manso Sainz

The Zeeman effect is of limited utility for probing the magnetism of the quiet solar chromosphere. The Hanle effect in some spectral lines is sensitive to such magnetism, but the interpretation of the scattering polarization signals…

Solar and Stellar Astrophysics · Physics 2021-04-21 Jan Jurcak , Jiri Stepan , Javier Trujillo Bueno

Solar magnetic fields leave their fingerprints in the polarization signatures of the emergent spectral line radiation. This occurs through a variety of rather unfamiliar physical mechanisms, not only via the Zeeman effect. In particular,…

Solar and Stellar Astrophysics · Physics 2009-09-25 J. Trujillo Bueno

This paper reviews the current state of our understanding of high-speed solar wind acceleration in coronal holes. Observations by SOHO, coupled with interplanetary particle measurements going back several decades, have put strong…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

Knowledge of the structure of the coronal magnetic field is important for our understanding of many solar activity phenomena, e.g. flares and CMEs. However, the direct measurement of coronal magnetic fields is not possible with present…

Astrophysics · Physics 2020-01-29 T. Wiegelmann , T. Neukirch

The shape and dynamics of coronal mass ejections (CMEs) vary significantly based on the instrument and wavelength used. This has led to significant debate about the proper definitions of CME/shock fronts, pile-up/compression regions, and…

Solar and Stellar Astrophysics · Physics 2025-08-27 Oleg Stepanyuk , Kamen Kozarev

Two sequences of solar images obtained by the Transition Region and Coronal Explorer in three UV passbands are studied using wavelet and Fourier analysis and compared to the photospheric magnetic flux measured by the Michelson Doppler…

Magnetic field extrapolation is an important tool to study the three-dimensional (3D) solar coronal magnetic field which is difficult to directly measure. Various analytic models and numerical codes exist but their results often drastically…

Solar and Stellar Astrophysics · Physics 2017-06-28 Aiying Duan , Chaowei Jiang , Qiang Hu , Huai Zhang , G. Allen Gary , S. T. Wu , Jinbin Cao

When the polarimetric sensitivity and the angular resolution exceed a threshold, magnetic fields show up almost everywhere on the solar surface. Here I revise the observational properties of the weakest polarization signals, which appear in…

Astrophysics · Physics 2007-05-23 J. Sanchez Almeida

Coronal mass ejections (CMEs) are thought to drive collisionless shocks in the solar corona, which in turn have been shown capable of accelerating solar energetic particles (SEPs) in minutes. It has been notoriously difficult to extract…

Solar and Stellar Astrophysics · Physics 2015-06-19 Kamen A. Kozarev , John C. Raymond , Vasili V. Lobzin , Michael Hammer

Numerical models of the solar wind and coronal mass ejections (CMEs) utilize photospheric magnetic field observations to prescribe the inner boundary conditions for the plasma solutions. These magnetic field data are available to the…

Solar and Stellar Astrophysics · Physics 2026-02-03 Nishtha Sachdeva , Zhenguang Huang , Gabor Toth , Hongfan Chen , Ward B. Manchester , Bart van der Holst

Magnetic arcades in the solar atmosphere, or coronal loops, are common structures known to host magnetohydrodynamic (MHD) waves and oscillations. Of particular interest are the observed properties of transverse loop oscillations, such as…

Solar and Stellar Astrophysics · Physics 2021-06-16 Farhad Allian , Rekha Jain

Coronal holes are the coolest and darkest regions of the solar atmosphere, 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…

Solar and Stellar Astrophysics · Physics 2011-09-21 D. Banerjee , G. R. Gupta , L. Teriaca

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 apply a new method to determine the magnetic field in coronal loops using observations of coronal loop oscillations. We analyze seven Doppler shift oscillation events detected by SUMER in the hot flare line Fe XIX to obtain oscillation…

Astrophysics · Physics 2008-11-26 Tongjiang Wang , Davina E. Innes , Jiong Qiu