High-Resolution Photography of the Solar Chromosphere. XXIII. Direct Measurement of the Optical Thickness of H alpha Solar Loops
Abstract
A method has been devised which, under appropriate observational circumstances, enables a direct determination to be made of the optical thickness t(L) of high-rising H-alpha solar loops observed on the disk. It is applicable to both bright and dark loops and requires no knowledge of the source function in the loop; it is best adapted to optically thin ones. The technique has been successfully applied to four loops observed under various circumstances, giving values of t(L) ranging from 0.06 to 1.3. It is not restricted to H-alpha loops but, in principle, could also be applied to chromospheric and coronal fine structures observed in the visible, EUV, and X-ray regions.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1986
- DOI:
- 10.1086/163962
- Bibcode:
- 1986ApJ...301..989B
- Keywords:
-
- Astronomical Photography;
- Chromosphere;
- Coronal Loops;
- Optical Thickness;
- Solar Prominences;
- Fine Structure;
- H Alpha Line;
- Solar Physics;
- SUN: CHROMOSPHERE;
- SUN: PROMINENCES