scholarly journals Analog Video Magnetograms in Real Time

1971 ◽  
Vol 43 ◽  
pp. 76-83 ◽  
Author(s):  
R. C. Smithson ◽  
R. B. Leighton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Solar Spectrum ◽  
Zeeman Splitting ◽  
The Other ◽  
Line Of Sight ◽  
Zero Field ◽  
The Sun ◽  
Solar Magnetic Fields

For many years solar magnetic fields have been measured by a variety of techniques, all of which exploit the Zeeman splitting of lines in the solar spectrum. One of these techniques (Leighton, 1959) involves a photographic subtraction of two monochromatic images to produce a picture of the Sun in which the line-of-sight component of the solar magnetic field appears as various shades of gray. In a magnetogram made by this method, zero field strength appears as neutral gray, while magnetic fields of one polarity or the other appear as lighter or darker areas, respectively. Figure 1 shows such a magnetogram.

scholarly journals Manifestations of Solar Magnetic Fields

1998 ◽  
Vol 11 (2) ◽  
pp. 857-860
Author(s):  
S.K. Solanki
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Magnetic Activity ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
Quiet Sun ◽  
Solar Magnetic Activity

AbstractThe magnetism of the Sun manifests itself in innumerable ways, many of which constitute what is referred to as solar magnetic activity, while others are counted among the phenomena of the quiet Sun. After a brief overview of the structure of the solar magnetic field, a few examples of its manifestations are pointed out.

RSFP PREDICTIONS FOR TRANSVERSE SOLAR MAGNETIC FIELD DISTRIBUTION FROM SOLAR NEUTRINO DATA

1998 ◽  
Vol 13 (15) ◽  
pp. 1163-1170 ◽  
Author(s):  
B. C. CHAUHAN ◽  
U. C. PANDEY ◽  
S. DEV
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Distribution ◽  
Magnetic Moment ◽  
Solar Neutrino ◽  
Solar Magnetic Field ◽  
Magnetic Field Distribution ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
The Magnetic Field

Even though the standard solar model (SSM) has been very successful in predicting the thermal and nuclear evolution of the Sun, it does not throw enough light on solar magnetic activity. In the absence of a generally accepted theory of solar dynamo, various general arguments have been put forth to constrain solar magnetic fields. In the absence of reliable knowledge of solar magnetic fields from available astrophysical data, it may be worthwhile to constrain the solar magnetic fields from solar neutrino observations assuming Resonant Spin-Flavor Precession (RSFP) to be responsible for the solar neutrino deficit. The configuration of solar magnetic field derived in this work is in reasonably good agreement with the magnetic field distribution proposed by Akhmedov et al. (Sov. Phys. JETP68, 250 (1989)). However, the magnetic field distribution in the radiation zone used by Pulido (Phys. Rep.211, 167 (1992)) is ruled out. The magnitude of the magnetic field in the radiation and convective zones of the Sun are very sensitive to the value chosen for the neutrino magnetic moment. However, any change in the value of neutrino magnetic moment does not affect the magnetic field distribution as it only scales the magnetic field strength at different points by the same amount.

RESOLUTION OF THE Be/B SOLAR NEUTRINO FLUX ANOMALY IN THE RESONANT SPIN-FLAVOR PRECESSION SCENARIO WITH TWISTING SOLAR MAGNETIC FIELDS

2000 ◽  
Vol 15 (05) ◽  
pp. 351-360
Author(s):  
S. DEV ◽  
JYOTI DHAR SHARMA
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Seasonal Variations ◽  
Solar Neutrino ◽  
Solar Magnetic Field ◽  
Neutrino Flux ◽  
The Other ◽  
Complete Disappearance ◽  
Solar Magnetic Fields ◽  
Solar Neutrino Flux

The Be/B neutrino flux anomaly has been examined within the framework of the resonant spin-flavor precession scenario with twisting solar magnetic fields. It is found that the twist of the toroidal component of the solar magnetic field, leads naturally to a complete disappearance of 7 Be neutrinos emerging from one of the solar hemispheres. However, the 7 Be neutrino flux emerging from the other solar hemisphere with oppositely twisted magnetic field must survive completely. Thus, this scenario predicts seasonal variations of the 7 Be neutrino flux to be observed in the Borexino experiment.

scholarly journals Progress in the Measurement of Solar Magnetic Fields

1993 ◽  
Vol 141 ◽  
pp. 149-155 ◽  
Author(s):  
Guoxiang Ai
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
White Light ◽  
Historical Development ◽  
Solar Magnetic Field ◽  
Solar Physics ◽  
Monochromatic Light ◽  
Velocity Fields ◽  
Solar Magnetic Fields ◽  
Optical Instruments

AbstractThe historical development of optical instruments for solar physics is outlined, from white light to unpolarized and polarized monochromatic light, to Stokes profiles and simultaneous fields of view, from points to lines, plane to cube. An evolutionary series and classificaton of instruments for the solar magnetic field is described. As a next step the 2-D real time polarizing spectrograph has been proposed. The planned instruments in China for measurements of solar magnetic and velocity fields are briefly introduced.

scholarly journals Sector Structure of the Solar Magnetic Field

1971 ◽  
Vol 43 ◽  
pp. 744-753 ◽  
Author(s):  
John M. Wilcox
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Solar Magnetic Field ◽  
Photospheric Magnetic Field ◽  
The Other ◽  
The Sun ◽  
Sector Structure ◽  
Sector Boundary ◽  
The North

The solar sector structure consists of a boundary in the north-south direction such that on one side of the boundary the large-scale weak photospheric magnetic field is predominantly directed out of the Sun, and on the other side of the boundary this field is directed into the Sun. The region westward of a solar sector boundary tends to be unusually quiet and the region eastward of a solar sector boundary tends to be unusually active. This tendency is discussed in terms of flares, coronal enhancements, plage structure and geomagnetic response.

scholarly journals Starspots Magnetic field by transit mapping

2013 ◽  
Vol 9 (S302) ◽  
pp. 220-221
Author(s):  
Adriana Válio ◽  
Eduardo Spagiari
Keyword(s):  
Magnetic Field ◽  
Light Curve ◽  
Field Component ◽  
Solar Magnetic Field ◽  
Line Of Sight ◽  
The Sun ◽  
Using Data ◽  
The Magnetic Field ◽  
Spot Temperature

AbstractSunspots are important signatures of the global solar magnetic field cycle. It is believed that other stars also present these same phenomena. However, today it is not possible to observe directly star spots due to their very small sizes. The method applied here studies star spots by detecting small variations in the stellar light curve during a planetary transit. When the planet passes in front of its host star, there is a chance of it occulting, at least partially, a spot. This allows the determination of the spots physical characteristics, such as size, temperature, and location on the stellar surface. In the case of the Sun, there exists a relation between the magnetic field and the spot temperature. We estimate the magnetic field component along the line-of-sight and the intensity of sunspots using data from the MDI instrument on board of the SOHO satellite. Assuming that the same relation applies to other stars, we estimate spots magnetic fields of CoRoT-2 and Kepler-17 stars.

scholarly journals Large-Scale Solar Magnetic Fields

1976 ◽  
Vol 71 ◽  
pp. 47-67 ◽  
Author(s):  
V. Bumba
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Distribution ◽  
Large Scale ◽  
Solar Magnetic Field ◽  
Magnetic Measurements ◽  
Preliminary Investigation ◽  
Longitudinal Distribution ◽  
Solar Magnetic Fields ◽  
Background Fields

The characteristics of the large-scale distribution of the solar magnetic fields on the basis of a series of solar magnetic synoptic charts covering more than 15 years of observations are given. The major part of our information concerns the morphology and only some results deal with the kinematics of the field distribution. Results of averaged solar magnetic field fluxes and polarity reversal studies as well as of preliminary investigation of the very-low angular resolution magnetic measurements are given. The regular zonal and sectoral distribution of photospheric background fields, the different role or visibility of structures in both polarities is discussed. The reflection of both main types of the longitudinal distribution of large-scale solar background magnetic fields (the 27-day, the 28–29-day successions, the ‘supergiant’ structures) in the interplanetary magnetic field distribution is also considered.

scholarly journals Possible Origins of the 12µ Emission Lines in the Solar Spectrum

1983 ◽  
Vol 71 ◽  
pp. 327-330
Author(s):  
Leo Goldberg
Keyword(s):  
Magnetic Field ◽  
Solar Spectrum ◽  
Field Measurements ◽  
Zeeman Splitting ◽  
Emission Lines ◽  
Line Of Sight ◽  
Central Component ◽  
Full Width ◽  
Magnetic Field Measurements ◽  
The Continuum

Braut and Noyes (1982,1983) have reported the detection of about 40 unidentified emission lines near 12µ in the solar spectrum. The strongest lines, at 811.578 cm-1 and 818.062 cm-1, respectively, appear as broad, shallow absorption lines, less than 3% deep, with central, emission reversals projecting 5-10% above the continuum. The emission lines strengthen at the limb and over spot penumbrae but seem to be absent over spot umbrae. The full width at half-intensity of the emission lines is about 5 km/sec, but the absorption widths are more than 10 times as broad. Over spot penumbrae, the Zeeman splitting of the emission lines is striking. The lines have the appearance of a Zeeman triplet; the central component is nearly absent at the center of the disk but is very strong near the limb where the field is viewed perpendicularly to the line of sight. The splitting over spot penumbrae is about 10 times the width of the central component, and is consistent with that of a spectral line with a Landé g-factor of unity in a magnetic field of 1500 gauss. Braut and Noyes (1982, 1983) point out that the 12 u lines are a potentially powerful tool for magnetic field measurements in stars. Further observational details will be found in their referenced papers.

scholarly journals [no title]

1977 ◽  
Vol 4 (2) ◽  
pp. 223-239 ◽  
Author(s):  
J. Harvey
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spatial Resolution ◽  
Small Scale ◽  
Solar Photosphere ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
Structure And Dynamics ◽  
Physical Problems ◽  
Observational Techniques

If the Sun is observed like a star, without spatial resolution, its magnetic field seldom exceeds 1 Gauss. But with high spatial resolution the field is seen to be largely concentrated into kG structures. Observations of the structure and dynamics of solar magnetic fields can therefore provide a guide to the nature of magnetic fields of other stars which cannot be resolved. Solar activity and the structure of the chromosphere and inner corona are intimately linked with magnetism and a complete understanding of these features often depends on magnetic field details. There are unsolved physical problems involving solar magnetic fields which have challenged many physicists. For example, confinement of small-scale fields in kG structures is a problem of current interest (Parker, 1976; Piddington, 1976; Spruit, 1976). Solar observers are no less challenged since the Sun presents us with a complicated magnetic field having a range of scales from global to less than the scale of our best observations as illustrated in Figures 1, 2, and 3. This paper is a survey of observational techniques and results at the small-scale end of the spectrum of sizes in the solar photosphere. This topic has been frequently reviewed (e.g. Athay, 1976; Beckers, 1976; Deubner, 1975; Howard, 1972; Mullan, 1974; Severny, 1972; Stenflo, 1975) so that recent work is emphasized here.

scholarly journals Transient Events and Their Solar Magnetic Field

1998 ◽  
Vol 11 (2) ◽  
pp. 877-879
Author(s):  
J.-C. Vial
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Magnetic Fields ◽  
Coronal Mass Ejections ◽  
Solar Magnetic Field ◽  
Solar Magnetic Fields ◽  
Radio Network ◽  
Excellent Review ◽  
X Ray ◽  
Transient Events

Excellent review papers have been presented in this session by S. Solanki (Manifestations of solar magnetic fields), K. Dere (Coronal Mass Ejections and interplanetary ejecta) and W. Droege (Particle acceleration by waves and fields) and the relevant texts can be found in this volume.The Joint Discussion benefited from three contributed papers: X-Ray/Radio network flares of the quiet Sun by A.O. Benz, S. Krucker, L.W. Acton, and T.S. Bastian (presented by A.O. Benz) Radio observations of coronal X-ray jets by M.R. Kundu

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