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Related papers: 3D Coronal Density Reconstruction and Retrieving t…

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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…

Observations suggest a power-law relation between the coronal emission in X-rays, $L_{\rm{X}}$, and the total (unsigned) magnetic flux at the stellar surface, $\Phi$. The physics basis for this relation is poorly understood. We use…

Solar and Stellar Astrophysics · Physics 2021-08-04 J. Zhuleku , J. Warnecke , H. Peter

Understanding the density structure of the solar corona is important for modeling both coronal heating and the solar wind. Direct measurements are difficult because of line-of-sight integration and possible unresolved structures. We present…

Solar and Stellar Astrophysics · Physics 2016-09-28 Michael Hahn , Daniel Wolf Savin

Magnetism defines the complex and dynamic solar corona. Coronal mass ejections (CMEs) are thought to be caused by stresses, twists, and tangles in coronal magnetic fields that build up energy and ultimately erupt, hurling plasma into…

A technique is described for measuring electrical currents in the solar corona. It uses radioastronomical polarization measurements of a spatially-extended radio source viewed through the corona. The observations yield the difference in the…

Astrophysics · Physics 2009-11-13 Steven R. Spangler

In this paper, I review the results of 3-D evolution of the inner heliosphere over the solar cycle #23, based on observations of interplanetary scintillation (IPS) made at 327 MHz using the Ooty Radio Telescope. The large-scale features of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

We report a solar coronal split-band type II radio burst that was observed on 2016 March 16 with the Gauribidanur Radio Spectro-Polarimeter (GRASP) in the frequency range $\approx$\,90\,-\,50 MHz, and the Gauribidanur RadioheliograPH…

Solar and Stellar Astrophysics · Physics 2019-08-14 Anshu Kumari , R. Ramesh , C. Kathiravan , T. J. Wang , N. Gopalswamy

Three-dimensional null points are present in abundance in the solar corona, and the same is likely to be true in other astrophysical environments. Recent studies suggest that reconnection at such 3D nulls may play an important role in the…

Solar and Stellar Astrophysics · Physics 2011-09-28 D. I. Pontin , A. K. Al-Hachami , K. Galsgaard

We study extreme-ultraviolet emission line spectra derived from three-dimensional magnetohydrodynamic models of structures in the corona. In order to investigate the effects of increased magnetic activity at photospheric levels in a…

Solar and Stellar Astrophysics · Physics 2009-04-16 Pia Zacharias , Sven Bingert , Hardi Peter

Measurements of the magnetic field in the stellar coronae are extremely difficult. Recently, it was proposed that the magnetic-field-induced transition (MIT) of the Fe X 257 {\AA} line can be used to measure the coronal magnetic field of…

Solar and Stellar Astrophysics · Physics 2021-09-08 Yajie Chen , Xianyu Liu , Hui Tian , Xianyong Bai , Meng Jin , Wenxian Li , Yang Yang , Zihao Yang , Yuanyong Deng

We present a new method to extract the three-dimensional electron density profile and density compression ratio of shock fronts associated with Coronal Mass Ejections (CMEs) observed in white light coronagraph images. We demonstrate the…

Solar and Stellar Astrophysics · Physics 2018-01-16 Ryun-Young Kwon , Angelos Vourlidas

A novel method of using hard X-rays as a diagnostic for chromospheric density and magnetic structures is developed to infer sub-arcsecond vertical variation of magnetic flux tube size and neutral gas density.Using Reuven Ramaty High Energy…

Astrophysics · Physics 2009-11-13 E. P. Kontar , I. G. Hannah , A. L. MacKinnon

Due to the absence of direct measurement, the magnetic field in the solar corona is usually extrapolated from the photosphere in numerical way. At the moment, the nonlinear force-free field (NLFFF) model dominates the physical models for…

Solar and Stellar Astrophysics · Physics 2015-06-15 Chaowei Jiang , Xueshang Feng

Solar magnetic fields play a key role in understanding the nature of the coronal phenomena. Global coronal magnetic fields are usually extrapolated from photospheric fields, for which farside data is taken when it was at the frontside,…

Solar and Stellar Astrophysics · Physics 2022-04-28 Hyun-Jin Jeong , Yong-Jae Moon , Eunsu Park , Harim Lee

In the present work we study evolution of magnetic helicity in the solar corona. We compare the rate of change of a quantity related to the magnetic helicity in the corona to the flux of magnetic helicity through the photosphere and find…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , M. H. Yusuf , D. W. Longcope

Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of $5R_\odot$. We report on sensitive…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jason E. Kooi , Patrick D. Fischer , Jacob J. Buffo , Steven R. Spangler

We present the first reconstruction of the three-dimensional shape of magnetic loops in an active region from two different vantage points based on simultaneously recorded images. The images were taken by the two EUVI telescopes of the…

Astrophysics · Physics 2008-02-07 L. Feng , B. Inhester , S. K. Solanki , T. Wiegelmann , B. Podlipnik , R. A. Howard , J. -P. Wuelser

The understanding of the solar magnetic coronal structure is tightly linked to the shape of open field regions, specifically coronal holes. A dynamically evolving coronal hole coincides with the local restructuring of open to closed…

Magnetic reconnection is a fundamental mechanism in astrophysics. A common challenge in mimicking this process numerically in particular for the Sun is that the solar electrical resistivity is small compared to the diffusive effects caused…

Solar and Stellar Astrophysics · Physics 2023-07-05 Øystein Håvard Færder , Daniel Nóbrega-Siverio , Mats Carlsson

The coronal magnetic field is the prime driver behind many as-yet unsolved mysteries: solar eruptions, coronal heating, and the solar wind, to name a few. It is, however, still poorly observed and understood. We highlight key questions…