Physical Conditions in Limb Flares and Active Prominences.IV. Compersion of Active and Quiescent Prominences.
Abstract
Spectra of active and quiescent prominences appearing simultaneously at the limb of the sun are analyzed and discussed. The quiescent prominence shows a spectrum identical with that of the chromosphere at 1500 km, with strong lines of H, He I, and ionized metals and weak He ii. The active prominence shows strong He ii and very weak ionized metal lines The lines in the active prominence are very much broader The width of lines in either prominence is shown to depend on their excitation potential. It is proposed, as a result of many observations, that, except for strong lines such as those of hydrogen and Ca ii, the spectra of prominences fall into two sharply defined classes, depending on whether they are "hot" or "cool"
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1960
- DOI:
- 10.1086/146884
- Bibcode:
- 1960ApJ...131..717Z