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Related papers: The Solar Coronal Magnetic Field Measurements With…

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Adopting the thermal free-free emission mechanism, the coronal and chromospheric magnetic fields are derived from the polarization and spectral observations with the Nobeyama Radioheliograph at 1.76 cm. The solar active regions (AR) located…

Solar and Stellar Astrophysics · Physics 2018-02-14 A. Mouner , Abdelrazek M. K. Shaltout , M. M. Beheary , K. A. K. Gadallah , K. A. Edris

Non-linear force-free extrapolations are a common approach to estimate the 3D topology of coronal magnetic fields based on photospheric vector magnetograms. The force-free assumption is a valid approximation at coronal heights, but for the…

Coronal magnetic fields are well known to be one of the crucial parameters defining coronal physics and space weather. However, measuring the global coronal magnetic fields remains challenging. The polarization properties of coronal radio…

Solar and Stellar Astrophysics · Physics 2022-07-01 Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

The present work illustrates the potential of a new diagnostic technique that allows the measurement of the coronal magnetic field strength in solar active regions utilizing a handful of bright \ion[Fe x] and \ion[Fe xi] lines commonly…

Solar and Stellar Astrophysics · Physics 2020-12-02 E. Landi , R. Hutton , T. Brage , W. Li

The magnetic field plays a pivotal role in many fields of Astrophysics. This is especially true for the physics of the solar atmosphere. Measuring the magnetic field in the upper solar atmosphere is crucial to understand the nature of the…

Recent works demonstrated that remote sensing observations of shock waves propagating into the corona and associated with major solar eruptions can be used to derive the strength of coronal magnetic fields met by the shock over a very large…

Solar and Stellar Astrophysics · Physics 2016-08-22 Alessandro Bemporad , Roberto Susino , Federica Frassati , Silvano Fineschi

Magnetic field in the solar lower atmosphere can be measured by the use of the Zeeman and Hanle effects. In contrast, the coronal magnetic field well above the solar surface, which directly controls various eruptive phenomena, can not be…

Solar and Stellar Astrophysics · Physics 2010-01-05 P. F. Chen

The solar magnetic field is key to understanding the physical processes in the solar atmosphere. Nonlinear force-free codes have been shown to be useful in extrapolating the coronal field upward from underlying vector boundary data.…

Astrophysics · Physics 2008-02-29 T. Wiegelmann , J. K. Thalmann , C. J. Schrijver , M. L. Derosa , T. R. Metcalf

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…

Aims: We aim to achieve high spatial resolution as well as high polarimetric sensitivity, using an earth-based 1m-class solar telescope, for the study of magnetic fine structure on the Sun. Methods: We use a setup with 3 high-speed,…

Astrophysics · Physics 2009-11-13 M. J. van Noort , L. H. M. Rouppe van der Voort

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

Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal phenomena at all scales. We employed STEREO/COR1 data obtained during a deep minimum of solar activity in February 2008…

Solar and Stellar Astrophysics · Physics 2014-05-06 M. Kramar , V. Airapetian , Z. Mikić , J. Davila

Energy stored in the magnetic field in the solar atmosphere above active regions is a key driver of all solar activity (e.g., solar flares and coronal mass ejections), some of which can affect life on Earth. Radio observations provide a…

Solar and Stellar Astrophysics · Physics 2018-10-17 Gregory D. Fleishman , Gelu M. Nita , Stephen M. White , Dale E. Gary , Tim S. Bastian

The magnetic field governs the corona; hence it is a crucial parameter to measure. Unfortunately, existing techniques for estimating its strength are limited by strong assumptions and limitations. These techniques include photospheric or…

Solar and Stellar Astrophysics · Physics 2022-10-26 Juan Martinez-Sykora , Viggo H. Hansteen , Bart De Pontieu , Enrico Landi

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

One of the major science goals of the Visible Emission Line Coronagraph (VELC) payload aboard the Aditya-L1 mission is to map the coronal magnetic field topology and the quantitative estimation of longitudinal magnetic field on routine…

Instrumentation and Methods for Astrophysics · Physics 2021-09-22 K. Nagaraju , B. Raghavendra Prasad , Bhavana S. Hegde , Suresh Venkata Narra , D. Utkarsha , Amit Kumar , Jagdev Singh , Varun Kumar

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

Sunspots on the surface of the Sun are the observational signatures of intense manifestations of tightly packed magnetic field lines, with near-vertical field strengths exceeding 6,000 G in extreme cases. It is well accepted that both the…

An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric…

Astrophysics · Physics 2008-11-26 S. Robbins , C. J. Henney , J. W. Harvey

Recent observations have demonstrated the capability of mapping the solar coronal magnetic field using the technique of coronal seismology based on the ubiquitous propagating Alfvenic/kink waves through imaging spectroscopy. We established…

Solar and Stellar Astrophysics · Physics 2024-11-14 Yuhang Gao , Hui Tian , Tom Van Doorsselaere , Zihao Yang , Mingzhe Guo , Konstantinos Karampelas