greater than
are not indicated.
The following tabulation represents the resulting temperature scale for the hotter stars. It must be remembered that
is here the derived quantity, whereas in [Table XX] it was the known quantity used for calibration.
[TABLE XXI]
| Atom | Ionization Potential | Excitation Potential | Max. | |
|---|---|---|---|---|
| He+ | 54.2 | 48.2 | 35000° | |
| C+ | 24.3 | 18.0 | l6000 | |
| He | 24.7 | 21.1 | 10000 | |
| Si++ | 31.7 | 4.8 | 18000 | |
| Si+++ | 45.0 | 24.0 | 25000 |
The values given in the preceding table constitute the only contribution that can be made by this form of ionization theory to the formation of a stellar temperature scale. Values assigned to intermediate classes must be conjectural. From the observed changes of intensity from class to class, temperatures may be interpolated roughly, and a temperature scale, formed on these general grounds, is reproduced in [Table XXII]. Values not derived from observed maxima are italicized.