The mutual attraction of magnetic knots.
Abstract
It is observed that the magnetic knots associated with active regions on the sun have an attraction for each other during the formative period of the active regions, when new magnetic flux is coming to the surface. The attraction disappears when new flux ceases to rise through the surface. Then the magnetic spots and knots tend to come apart, leading to disintegration of the sunspots previously formed. The dissolution of the fields is to be expected, as a consequence of the magnetic repulsion of knots of like polarity and as a consequence of the hydromagnetic exchange instability. The purpose of this paper is to show that the mutual attraction of knots during the formative stages of a sunspot region may be understood as the mutual hydrodynamic attraction of the rising flux tubes. Two rising tubes attract each other, as a consequence of the wake of the leading tube when one is moving behind the other, and as a consequence of the Bernoulli effect when rising side by side.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1978
- DOI:
- 10.1086/156148
- Bibcode:
- 1978ApJ...222..357P
- Keywords:
-
- Astronomical Models;
- Magnetohydrodynamic Stability;
- Solar Magnetic Field;
- Sunspots;
- Attraction;
- Bernoulli Theorem;
- Coalescing;
- Equations Of Motion;
- Lagrange Coordinates;
- Magnetic Flux;
- Magnetohydrodynamic Waves;
- Navier-Stokes Equation;
- Reynolds Number;
- Solar Physics;
- Magnetic Fields:Solar Active Regions;
- Magnetic Fields:Sunspots;
- Solar Magnetic Fields: Knots