scholarly journals The Toroidal Magnetic Field inside the Sun

1991 ◽  
Vol 130 ◽  
pp. 187-189
Author(s):  
V.N. Krivodubskij ◽  
A.E. Dudorov ◽  
A.A. Ruzmaikin ◽  
T.V. Ruzmaikina
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Convection Zone ◽  
The Sun ◽  
Poloidal Magnetic Field ◽  
Radial Gradient ◽  
The Core ◽  
Large Scale Magnetic Field ◽  
Magnetic Buoyancy ◽  
The Magnetic Field

Analysis of the fine structure of the solar oscillations has enabled us to determine the internal rotation of the Sun and to estimate the magnitude of the large-scale magnetic field inside the Sun. According to the data of Duvall et al. (1984), the core of the Sun rotates about twice as fast as the solar surface. Recently Dziembowski et al. (1989) have showed that there is a sharp radial gradient in the Sun’s rotation at the base of the convection zone, near the boundary with the radiative interior. It seems to us that the sharp radial gradients of the angular velocity near the core of the Sun and at the base of the convection zone, acting on the relict poloidal magnetic field Br, must excite an intense toroidal field Bф, that can compensate for the loss of the magnetic field due to magnetic buoyancy.

scholarly journals Large-Scale Internal Magnetic Field of the Sun

1990 ◽  
Vol 138 ◽  
pp. 391-394
Author(s):  
A.E. Dudorov ◽  
V.N. Krivodubskij ◽  
A.A. Ruzmaikin ◽  
T.V. Ruzmaikina
Keyword(s):  
Magnetic Field ◽  
Differential Rotation ◽  
Large Scale ◽  
The Sun ◽  
Poloidal Magnetic Field ◽  
The Core ◽  
Torsional Waves ◽  
Formation And Evolution ◽  
Field Lines ◽  
The Magnetic Field

The behaviour of the magnetic field during the formation and evolution of the Sun is investigated. It is shown that an internal poloidal magnetic field of the order of 104 − 105 G near the core of the Sun may be compatible with differential rotation and with torsional waves, travelling along the magnetic field lines (Dudorov et al., 1989).

scholarly journals Numerical Simulations of Large-scale Solar Magnetic Fields

1985 ◽  
Vol 38 (6) ◽  
pp. 999 ◽  
Author(s):  
CR DeVore ◽  
NR Sheeley Jr ◽  
JP Boris ◽  
TR Young Jr ◽  
KL Harvey
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Large Scale ◽  
Sunspot Cycle ◽  
Active Regions ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
Field Patterns ◽  
Large Scale Magnetic Field ◽  
The Magnetic Field

We have solved numerically a transport equation which describes the evolution of the large-scale magnetic field of the Sun. Data derived from solar magnetic observations are used to initialize the computations and to account for the emergence of new magnetic flux during the sunspot cycle. Our objective is to assess the ability of the model to reproduce the observed evolution of the field patterns. We discuss recent results from simulations of individual active regions over a few solar rotations and of the magnetic field of the Sun over sunspot cycle 21.

scholarly journals The Large-Scale Magnetic Field Structure Near the Galactic Centre

1990 ◽  
Vol 140 ◽  
pp. 369-372
Author(s):  
Wolfgang Reich
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Large Scale ◽  
Field Structure ◽  
Galactic Centre ◽  
Poloidal Magnetic Field ◽  
Magnetic Field Structure ◽  
Large Scale Magnetic Field ◽  
Centre Region ◽  
The Magnetic Field

High frequency polarization observations reveal the existence of a poloidal magnetic field structure in the Galactic Centre region on scales of about 200 pc. At lower frequencies large non–thermal spurs are seen tracing the magnetic field up to kpc distances from the Galactic Centre.

scholarly journals The Transfer of Large-scale Magnetic Field by Radial Inhomogeneity of the Material Density in the Rotating Convection Zone

1991 ◽  
Vol 130 ◽  
pp. 190-192
Author(s):  
V.N. Krivodubskij ◽  
L.L. Kichatinov
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Large Scale ◽  
Convection Zone ◽  
Turbulent Plasma ◽  
The Sun ◽  
Material Density ◽  
Large Scale Magnetic Field ◽  
Radial Inhomogeneity ◽  
The Mean

AbstractThe influence of rotation on the transfer of the mean magnetic field of the Sun, caused by the radial inhomogeneity of the solar turbulent plasma density, is investigated. It turns out that the transfer directions of the poloidal and toroidal magnetic fields do not coincide.

scholarly journals Non-Linear Diamagnetic Transport of the Large-Scale Magnetic Field in the Solar Convection Zone

1993 ◽  
Vol 157 ◽  
pp. 49-50
Author(s):  
V.N. Krivodubskij
Keyword(s):  
Magnetic Field ◽  
Turbulence Intensity ◽  
Large Scale ◽  
Convection Zone ◽  
Back Reaction ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Large Scale Magnetic Field ◽  
Magnetic Buoyancy ◽  
The Mean

The mean magnetic field transport due to inhomogeneity of the turbulence intensity is considered taking the field back reaction on motion into account. In spite of the magnetic quenching, the downward diamagnetic pumping is still powerful enough to keep the fields of 3 to 4 kG strength near the SCZ base against the magnetic buoyancy.

scholarly journals How to make the Sun look less like the Sun and more like a star?

2016 ◽  
Vol 12 (S328) ◽  
pp. 237-239
Author(s):  
A. A. Vidotto
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Vector Fields ◽  
Radial Component ◽  
Field Vector ◽  
Small Scale ◽  
General Context ◽  
The Sun ◽  
Flux Transport ◽  
Large Scale Magnetic Field

AbstractSynoptic maps of the vector magnetic field have routinely been made available from stellar observations and recently have started to be obtained for the solar photospheric field. Although solar magnetic maps show a multitude of details, stellar maps are limited to imaging large-scale fields only. In spite of their lower resolution, magnetic field imaging of solar-type stars allow us to put the Sun in a much more general context. However, direct comparison between stellar and solar magnetic maps are hampered by their dramatic differences in resolution. Here, I present the results of a method to filter out the small-scale component of vector fields, in such a way that comparison between solar and stellar (large-scale) magnetic field vector maps can be directly made. This approach extends the technique widely used to decompose the radial component of the solar magnetic field to the azimuthal and meridional components as well, and is entirely consistent with the description adopted in several stellar studies. This method can also be used to confront synoptic maps synthesised in numerical simulations of dynamo and magnetic flux transport studies to those derived from stellar observations.

scholarly journals Reconstruction of Sun-as-Star Magnetic Field Structure and Evolution Using Filament Observations

1998 ◽  
Vol 167 ◽  
pp. 493-496
Author(s):  
Dmitri I. Ponyavin
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Large Scale ◽  
Solar Magnetic Field ◽  
Close Association ◽  
Field Structure ◽  
The Sun ◽  
Magnetic Field Structure ◽  
Large Scale Magnetic Field ◽  
Field Organization

AbstractA technique is used to restore the magnetic field of the Sun viewed as star from the filament distribution seen on Hα photographs. For this purpose synoptic charts of the large-scale magnetic field reconstructed by the McIntosh method have been compared with the Sun-asstar solar magnetic field observed at Stanford. We have established a close association between the Sun-as-star magnetic field and the mean magnetic field inferred from synoptic magnetic field maps. A filtering technique was applied to find correlations between the Sun-as-star and large-scale magnetic field distributions during the course of a solar cycle. The correlations found were then used to restore the Sun-as-star magnetic field and its evolution in the late 1950s and 1960s, when such measurements of the field were not being made. A stackplot display of the inferred data reveals large-scale magnetic field organization and evolution. Patterns of the Sun-as-star magnetic field during solar cycle 19 were obtained. The proposed technique can be useful for studying the solar magnetic field structure and evolution during times with no direct observations.

scholarly journals Sun-like Stars: magnetic fields, cycles and exoplanets

2015 ◽  
Vol 11 (A29A) ◽  
pp. 360-364
Author(s):  
Rim Fares
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Large Scale ◽  
Observational Constraints ◽  
The Sun ◽  
Field Generation ◽  
Large Scale Magnetic Field ◽  
Planetary Orbits ◽  
Activity Cycles ◽  
Magnetic Cycles

AbstractIn Sun-like stars, magnetic fields are generated in the outer convective layers. They shape the stellar environment, from the photosphere to planetary orbits. Studying the large-scale magnetic field of those stars enlightens our understanding of the field properties and gives us observational constraints for field generation dynamo models. It also sheds light on how “normal” the Sun is among Sun-like stars. In this contribution, I will review the field properties of Sun-like stars, focusing on solar twins and planet hosting stars. I will discuss the observed large-scale magnetic cycles, compare them to stellar activity cycles, and link that to what we know about the Sun. I will also discuss the effect of large-scale stellar fields on exoplanets, exoplanetary emissions (e.g. radio), and habitability.

scholarly journals Probing interstellar magnetic fields with Supernova remnants

2008 ◽  
Vol 4 (S259) ◽  
pp. 75-80 ◽  
Author(s):  
Roland Kothes ◽  
Jo-Anne Brown
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Supernova Remnants ◽  
Large Scale ◽  
Galactic Plane ◽  
Field Configuration ◽  
Large Scale Magnetic Field ◽  
Rotation Measure ◽  
Field Lines ◽  
The Magnetic Field

AbstractAs Supernova remnants expand, their shock waves are freezing in and compressing the magnetic field lines they encounter; consequently we can use Supernova remnants as magnifying glasses for their ambient magnetic fields. We will describe a simple model to determine emission, polarization, and rotation measure characteristics of adiabatically expanding Supernova remnants and how we can exploit this model to gain information about the large scale magnetic field in our Galaxy. We will give two examples: The SNR DA530, which is located high above the Galactic plane, reveals information about the magnetic field in the halo of our Galaxy. The SNR G182.4+4.3 is located close to the anti-centre of our Galaxy and reveals the most probable direction where the large-scale magnetic field is perpendicular to the line of sight. This may help to decide on the large-scale magnetic field configuration of our Galaxy. But more observations of SNRs are needed.

scholarly journals Coronal ejections from convective spherical shell dynamos

2011 ◽  
Vol 7 (S286) ◽  
pp. 154-158 ◽  
Author(s):  
J. Warnecke ◽  
P. J. Käpylä ◽  
M. J. Mantere ◽  
A. Brandenburg
Keyword(s):  
Magnetic Field ◽  
Spherical Shell ◽  
Large Scale ◽  
Convection Zone ◽  
Three Dimensional ◽  
Simplified Model ◽  
Spherical Coordinates ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Large Scale Magnetic Field

AbstractWe present a three-dimensional model of rotating convection combined with a simplified model of a corona in spherical coordinates. The motions in the convection zone generate a large-scale magnetic field which is sporadically ejected into the outer layers above. Our model corona is approximately isothermal, but it includes density stratification due to gravity.

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