technetium star

A technetium star is a star whose spectrum reveals the presence of the element technetium. The first such stars were discovered in 1952 and provided the first direct evidence for stellar nucleosynthesis – the manufacture of heavier elements from lighter ones in stellar interiors. Because the most stable isotopes of technetium have half-lives of only a few million years, the only way this element could be present inside stars is if it had made there in the relatively recent past. Technetium is observed in some M stars, MS stars, MC stars, S stars, and C stars.