Major Hα Flares in Centers of Activity with very Small or no Spots
Abstract
Major Hα flares (importance ≥ 2) in plages with only small or no spots constitute a rare but well observed aspect of solar activity. Information relating to 83 such flares has been assembled and studied. In the years 1956-1968 these flares represented ∼ 7% of all confirmed flares of importance ≥ 2. In general, the flares were of unusually long duration and rose to maximum intensity slowly. A flash phase was often absent or poorly defined. In a number of cases, the flare emission included two bright filaments more or less parallel. The flares usually occurred during the late, flare-poor phase of a center of activity, and their outbreak did not presage a resurgence of activity in subsequent rotations. The flares were frequently associated with the position of dark filaments.
- Publication:
-
Solar Physics
- Pub Date:
- August 1970
- DOI:
- 10.1007/BF00153560
- Bibcode:
- 1970SoPh...13..401D
- Keywords:
-
- Flare;
- Solar Activity;
- Energetic Particle;
- Geomagnetic Storm;
- Particle Emission