Spiral filaments โ The signature of sing
โ
F. M. Hu; M. T. Song; Q. Z. Liu; H. S. Ji
๐
Article
๐
1996
๐
Springer
๐
English
โ 535 KB
A large delta spot (active region NOAA 6891, October 23-November 4, 1991) is analysed, and it is found that some spiral filaments across the spot can be regarded as signatures of a singular point entity (SPE) which lies near a separator of this complicated magnetic field region. Near such an entity,