Supergiants are the element factories of our universe. The nuclear fusion reactions occurring are H→ He, He→ C, C→ Ne, Ne→ O, O→ Si and Si→ Fe.
Betelgeuse in the constellation Orion is a super red giant. It is about 20 times as massive as the Sun. The lifetime of this type of star is relatively short by comparison with the Sun – millions of years as opposed to billions of years.
Acknowledgement: A. Dupree (CfA), R. Gilliland (STScI), NASA