scholarly journals MODELING MAGNETIC FIELD STRUCTURE OF A SOLAR ACTIVE REGION CORONA USING NONLINEAR FORCE-FREE FIELDS IN SPHERICAL GEOMETRY

2012 ◽  
Vol 760 (1) ◽  
pp. 47 ◽  
Author(s):  
Y. Guo ◽  
M. D. Ding ◽  
Y. Liu ◽  
X. D. Sun ◽  
M. L. DeRosa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Spherical Geometry ◽  
Field Structure ◽  
Solar Active Region ◽  
Magnetic Field Structure ◽  
Nonlinear Force ◽  
Free Fields

scholarly journals Evolution of a Filament/CH/Magnetic Field Complex

1998 ◽  
Vol 167 ◽  
pp. 393-396
Author(s):  
B.A. Ioshpa ◽  
E.I. Mogilevsky ◽  
V.N. Obridko
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Magnetic Fields ◽  
Large Scale ◽  
Coronal Holes ◽  
Field Structure ◽  
Potential Approximation ◽  
Magnetic Field Structure ◽  
Single Complex ◽  
The Magnetic Field

AbstractSOHO and YOHKOH images, as well as Hα filtergrams and magnetograms from IZMIRAN have been used to analyze the evolution of the related solar phenomena – filament, active region, and accompanying pair of coronal holes – during six solar rotations, with an emphasis on the events observed during August–September, 1996. The whole complex has been considered against the large–scale magnetic fields calculated under the potential approximation. A peculiar point has been found along the changing filament. It is shown that the phenomena under investigation (filament, active region, and coronal hole) form a single complex connected with the magnetic field structure.

scholarly journals An Attempt to Associate Observed Photospheric Motions with the Magnetic Field Structure and Flare Occurrence in an Active Region

1971 ◽  
Vol 43 ◽  
pp. 435-442 ◽  
Author(s):  
M. J. Martres ◽  
I. Soru-Escaut ◽  
J. Rayrole
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Empirical Evidence ◽  
Active Regions ◽  
Field Structure ◽  
Magnetic Field Structure ◽  
Abrupt Changes ◽  
The Magnetic Field

We have tried to find empirical evidence for the role of photospheric motions in the building up of the flare productive magnetic patterns in Active Regions.The bright Hα faculae are associated with V∥ structures different from a classical Evershed flow and particularly ‘anomalous’ in the regions and periods of high flare occurrence. The flares observed occurred at ‘crossings’ of the lines V∥ = 0(V ≠ 0) and H∥ = 0 and at places where V∥ = 0 showed abrupt changes of direction. It is suggested that these anomalous V∥ structures are evidence of vortex motions.

scholarly journals Evolution of the Nonpotential Magnetic Field in the Solar Active Region 12673 Based on a Nonlinear Force-free Modeling

2021 ◽  
Vol 908 (2) ◽  
pp. 132
Author(s):  
Daiki Yamasaki ◽  
Satoshi Inoue ◽  
Shin’ichi Nagata ◽  
Kiyoshi Ichimoto
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Solar Active Region ◽  
Nonlinear Force

scholarly journals The Magnetic Be Star Sigma Orionis E

1987 ◽  
Vol 92 ◽  
pp. 82-83 ◽  
Author(s):  
C. T. Bolton ◽  
A. W. Fullerton ◽  
D. Bohlender ◽  
J. D. Landstreet ◽  
D. R. Gies
Keyword(s):  
Magnetic Field ◽  
Field Structure ◽  
High Signal ◽  
Rotational Period ◽  
Magnetic Field Structure ◽  
The Past ◽  
Distribution Of Elements ◽  
Be Star ◽  
Hα Emission ◽  
The Magnetic Field

Over the past two years, we have obtained high resolution high signal/noise (S/N) spectra of the magnetic Be star σ Ori E at the Canada-France-Hawaii Telescope and McDonald Observatory. These spectra, which cover the spectral regions 399-417.5 and 440-458.5 nm and the Hα line and have typical S/N>200 and spectral resolution ≃0.02 nm, were obtained at a variety of rotational phases in order to study the magnetic field structure, the distribution of elements in the photosphere, and the effects of the magnetic field on the emission envelope. Our analysis of these spectra confirms, refines and extends the results obtained by Landstreet & Borra (1978), Groote & Hunger (1982 and references therein), and Nakajima (1985).The Hα emission is usually double-peaked, but it undergoes remarkable variations with the 1.19081 d rotational period of the star, which show that the emitting gas is localized into two regions which co-rotate with the star.

scholarly journals Propagation of an MHD Shock in the Vicinity of a Magnetic Neutral Sheet

1980 ◽  
Vol 91 ◽  
pp. 323-326
Author(s):  
D. J. Mullan ◽  
R. S. Steinolfson
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Corona ◽  
Large Scale ◽  
Field Structure ◽  
Neutral Sheet ◽  
Solar Cosmic Rays ◽  
Magnetic Field Structure ◽  
Large Scale Magnetic Field ◽  
Highly Correlated

The acceleration of solar cosmic rays in association with certain solar flares is known to be highly correlated with the propagation of an MHD shock through the solar corona (Svestka, 1976). The spatial structure of the sources of solar cosmic rays will be determined by those regions of the corona which are accessible to the flare-induced shock. The regions to which the flare shock is permitted to propagate are determined by the large scale magnetic field structure in the corona. McIntosh (1972, 1979) has demonstrated that quiescent filaments form a single continuous feature (a “baseball stitch”) around the surface of the sun. It is known that helmet streamers overlie quiescent filaments (Pneuman, 1975), and these helmet streamers contain large magnetic neutral sheets which are oriented essentially radially. Hence the magnetic field structure in the low solar corona is characterized by a large-scale radial neutral sheet which weaves around the entire sun following the “baseball stitch”. There is therefore a high probability that as a shock propagates away from a flare, it will eventually encounter this large neutral sheet.

Sign in / Sign up

Export Citation Format

Share Document