Carbon Stars with Strong C^{13} and Lithium Spectral Features

Abstract

This paper describes the spectral characteristics of the type J subclass of carbon stars, in particular noting the positive correlation between strong C13 and lithium features. We list four new members of this class. The average temperature of this group is similar to that of late R stars, although the spread is considerable. The photometric colors are anomalously red. The strength of the Merrill-Sanford bands and of characteristic features of this group are not correlated. The ratio appears to be exceptionally low. Spallation and neutron irradiation probably produce the lithium and the C13. Key words: carbon stars - lithium lines - C12IC13 ratio