Transition-Region Blinkers - II. Active-Region Properties
Abstract
The distribution and general properties of events identified in an active region that have the same characteristics as quiet-Sun blinkers are discussed and named `active-region blinkers'. The events are identified using an automated scheme `BLinker Identification Program' (BLIP) which was designed for and tested on quiet-Sun blinkers. Like quiet-Sun blinkers, the active-region events are most easily identified in the 629 Å emission line from O v although evidence for them is also found in other extreme UV lines emitted from He i, O iii and O iv. Unlike quiet-Sun blinkers, however, they may also have coronal signatures in the lines Mg ix and Mg x. Their properties are very similar to those of quiet-Sun blinkers with mean lifetimes of 16-19 min, mean areas of 2.4-4.3×107 km2 and mean intensity enhancements factors of 1.8-3.3. Their global frequency of 7-28 s−1 is about 42%-700% higher than that for quiet-Sun blinkers. The blinkers discussed here are found above both active-region (plage) magnetic fields, as well as above the umbra and penumbra of a sunspot.
- Publication:
-
Solar Physics
- Pub Date:
- April 2002
- DOI:
- 10.1023/A:1015094119974
- Bibcode:
- 2002SoPh..206..249P
- Keywords:
-
- Magnetic Field;
- Active Region;
- General Property;
- Emission Line;
- Enhancement Factor