A Photometric Study of the Continuum and Seventeen Emission Lines in the Inner Solar Corona.
Abstract
Absolute intensities of the continuum and a number of emission lines between x 3300 and X 6800 have been measured as a function of position angle on spectrograms of the inner corona obtained by B. Lyot and M. K. Alyat the total eclipse of February 25,1952, at Khartoum. More detailed measurements were made in a bright coronal condensation on the west limb, where the continuum and the following emission lines were measurable: XX 3328, 3388, 3454, 3534, 3601, 3643, 3801, 3988, 4086, 4232, 4412, 5116, 5303, 5445, 5694, 6374, 6702. On the assumption that the condensation is axially symmetric, we have found the electron density and the emission as functions of distance from the axis of symmetry. The lines of lowest ionization potential show a decrease in emission at the center of the condensation while the continuum and the emission of the remaining lines show increasing concentration toward the center with increasing ionization potential. (An exception is X 3643, which behaves like a line of lower ionization potential than Ni xui.) X 3534 appears to be much too bright to be due to V x unless the abundance of vanadium is very much higher than current estimates for the photosphere.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1962
- DOI:
- 10.1086/147449
- Bibcode:
- 1962ApJ...136..956A