Published online by Cambridge University Press: 12 April 2016
The sequence of stars starting with type S and extending through the SC stars into the red carbon stars are brought into the following revised system of classification:
In this table X stands for the temperature type and the number to the right of the slant line is an abundance index which, as suggested by Ake (1978), is essentially a measure of C/O. Intensities of ZrO and TiO are given also.