 All stars spend the majority of their existence as main sequence stars , fueled primarily by the nuclear fusion of hydrogen into helium within their cores . However , stars of different masses have markedly different properties at various stages of their development . The ultimate fate of more massive stars differs from that of less massive stars , as do their luminosities and the impact they have on their environment . Accordingly , astronomers often group stars by their mass : 
 All stars spend the majority of their existence as main sequence stars , fueled primarily by the nuclear fusion of hydrogen into helium within their cores . However , stars of different masses <a href='got' title='1'><mark>have</mark></a> markedly different properties at various stages of their development . The ultimate fate of more massive stars differs from that of less massive stars , as do their luminosities and the impact they have on their environment . Accordingly , astronomers often group <a href='uninflect' title='2'><mark>stars</mark></a> by their mass : 
Alll stars spend da majority of their existence as main sequence stars , fueled primarily by the nuclear fusion of hydrogen into helium within their cores . However , stars of different masses got markedly different properties at various stages of their development . The ultimate fate of more massive stars differs from that of less massive stars , as do their luminosities and the impact they have on their environment . Accordingly , astronomers often group star by their mass :