Forerunners: outer rims of solar coronal transients.
Abstract
The large loop or blob-like transient events viewed in the white-light corona are rimmed by broad regions where the density is slightly enhanced above the pre-transient corona. Every one of the Skylab events studied for which sufficiently good Skylab coronagraph coverage is available shows this effect. The upper boundaries of these `forerunners' blend gradually into the background corona 1 to ≥2R⊙ above the transients' leading edges. In any single event, the coronal mass enhancement represented by the forerunner comprises up to 25% of the total excess mass present in the coronagraph's field of view and includes a much larger volume of the corona than previously attributed to the underlying transient. We have not yet seen a forerunner without an accompanying transient. Clearly, forerunners must be reckoned with in any proposed models of discrete outward coronal mass motions, because they indicate the presence of disturbed corona far ahead of the denser portions of the event.
- Publication:
-
Solar Physics
- Pub Date:
- November 1978
- DOI:
- 10.1007/BF00152340
- Bibcode:
- 1978SoPh...60..155J
- Keywords:
-
- Coronagraphs;
- Solar Corona;
- Stellar Mass Ejection;
- Astronomical Models;
- Skylab Program;
- Spaceborne Astronomy;
- Solar Physics;
- Large Volume;
- Single Event;
- Mass Motion;
- Transient Event;
- Leading Edge;
- Solar Corona:Transients