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Related papers: Secular variations in the solar corona shape accor…

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We have studied the corona as seen at the eclipses of 1878, 1900, 1901 and others. These eclipses occurred during extended sunspot minimum conditions. We compare these data with those of the recent solar minimum corona, using data from the…

Solar and Stellar Astrophysics · Physics 2010-02-01 P. G. Judge , J. Burkepile , G. de Toma , M. Druckmueller

Rotation is a significant characteristic of the Sun and other stars, and it plays an important role in understanding their dynamo actions and magnetic activities. In this study, the rotation of the solar chromospheric activity is…

Solar and Stellar Astrophysics · Physics 2020-10-22 Jing-Chen Xu , Peng-Xin Gao , Xiang-Jun Shi

The structure of electric current and magnetic helicity in the solar corona is closely linked to solar activity over the 11-year cycle, yet is poorly understood. As an alternative to traditional current-free "potential field"…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. R. Yeates , J. A. Constable , P. C. H. Martens

Low and mid-latitude coronal holes (CHs) observed on the Sun during the current solar activity minimum (from September 21, 2006, Carrington rotation (CR) 2048, until June 26, 2009 (CR 2084)) were analyzed using {\it SOHO}/EIT and STEREO-A…

Solar and Stellar Astrophysics · Physics 2015-05-18 V. Abramenko , V. Yurchyshyn , J. Linker , Z. Mikic , J. Luhmann , C. Lee

Three dimensional electron density distributions in the solar corona are reconstructed for 100 Carrington Rotations (CR 2054$-$2153) during 2007/03$-$2014/08 using the spherically symmetric method from polarized white-light observations…

Solar and Stellar Astrophysics · Physics 2017-07-25 Tongjiang Wang , Nelson L. Reginald , Joseph M. Davila , O. Chris St. Cyr , William T. Thompson

The topology of the coronal magnetic field produces a strong impact on the properties of the solar corona and presumably on the origin of the slow solar wind. To advance our understanding of this impact, we revisit the concept of so-called…

Solar and Stellar Astrophysics · Physics 2020-03-04 R. Lionello , V. S. Titov , Z. Mikić , J. A. Linker

Observations from the NASA Solar Dynamic Observatory Atmospheric Imaging Assembly were employed to investigate targeted physical properties of coronal active region structures across the entirety of Solar Cycle 24 (dates). This is the…

Solar and Stellar Astrophysics · Physics 2023-05-19 Daniel Gordon Gass , Robert William Walsh

Strong magnetic fields are of vital importance to the physics of the solar corona. They easily move a rarefied coronal plasma. Physical origin of the main structural element of the corona, the so-called coronal streamers, is discussed. It…

Solar and Stellar Astrophysics · Physics 2013-03-14 Boris Somov

Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from…

Solar and Stellar Astrophysics · Physics 2015-12-15 Judith de Patoul , Claire Foullon , Pete Riley

Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity…

Solar and Stellar Astrophysics · Physics 2014-02-24 I. G. Usoskin , G. Hulot , Y. Gallet , R. Roth , A. Licht , F. Joos , G. A. Kovaltsov , E. Thebault , A. Khokhlov

During the solar minimum STEREO observations show that the three-dimensional structure of the solar corona can be described well by a tilted bi-polar magnetic configuration. The slow solar wind is modeled using three-fluid model that…

Solar and Stellar Astrophysics · Physics 2010-04-28 Leon Ofman , Maxim Kramar

Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. We seek to determine if these diffuse…

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…

A variety of indices have been proposed in order to represent the many different observables modulated by the solar cycle. Most of these indices are highly correlated with each other owing to their intrinsic link with the solar magnetism…

Solar and Stellar Astrophysics · Physics 2017-05-22 Ilaria Ermolli , Kiyoto Shibasaki , Andrey Tlatov , Lidia van Driel-Gesztelyi

We study the relationship between decaying active region magnetic fields, coronal holes and the global coronal magnetic structure using Global Oscillations Network Group (GONG) synoptic magnetograms, Solar Terrestrial RElations Observatory…

Solar and Stellar Astrophysics · Physics 2015-06-16 Gordon Petrie , Karl Haislmaier

Information on the rotation rate of the corona, and its variation over latitude and solar cycle, is valuable for making global connections between the corona and the Sun, for global estimates of reconnection rates, and as a basic parameter…

Solar and Stellar Astrophysics · Physics 2022-04-06 Liam T. Edwards , David Kuridze , Thomas Williams , Huw Morgan

The current cycle minimum appears to be deeper and broader than recent cycle minima, and this minimum appears similar to the minima in the early 1900s. With the best-ever solar irradiance measurements from several different satellite…

Solar and Stellar Astrophysics · Physics 2010-03-25 Thomas N. Woods

The precise shape of the Sun is sensitive to the influence of gravity, differential rotation, local turbulence and magnetic fields. It has been previously shown that the solar shape exhibits asphericity that evolves with the 11-year cycle.…

Solar and Stellar Astrophysics · Physics 2018-08-15 A. G. Kosovichev , J. -P. Rozelot

This paper examines long-term temporal and spatial fluctuations in the solar rotation (more than four solar cycles) by investigating radio emission escapes from various layers of the solar atmosphere during the years 1967-2010. The flux…

Solar and Stellar Astrophysics · Physics 2021-07-06 Vivek Kumar Singh , Satish Chandra , Sanish Thomas , Som Kumar Sharma , Hari Om Vats

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the…