Originally classified as R and N stars, these are also known as carbon stars. (en.wikipedia.org)
The extreme temperatures and gas pressures in carbon stars are perhaps the only way extraterrestrial noble gases could be forced inside a fullerene, she explained. (astrobio.net)
In each case, Future Forests - a profit - making company set up by entrepreneur Dan Morrell - calculates the amount of carbon a star generates in a year. (theguardian.com)