Bright red variables of large amplitude in the Magellanic Clouds

Periods and epochs of maximum light are given for 17 red variables in the Magellanic Clouds. Spectroscopic observations of six SMC variables of large amplitude confirm membership and show that a wide range of carbon and heavy element enrichment occurs: in particular two stars are of type CS. The high luminosity of these stars and the absence of stars with a similar moderate degree of carbon enrichment from the intermediate-age clusters is explicable in terms of stellar evolution theory. A new discussion of the Harvard data for bright red variables in both Magellanic Clouds confirms the presence of two groups, of high and intermediate mass. (author)