 Eruptive variables are stars that experience sudden increases in luminosity because of flares or mass ejection events . This group includes protostars , Wolf @-@ Rayet stars , and flare stars , as well as giant and supergiant stars . 
 Eruptive variables <a href='drop_aux' title='1'><mark>are</mark></a>stars <a href='null_relcl' title='2'><mark>that</mark></a>experience sudden increases in luminosity because of flares or mass ejection events . This group <a href='uninflect' title='3'><mark>includes</mark></a> protostars , Wolf @-@ Rayet stars , and flare stars , as well as giant and supergiant stars . 
Eruptive variables stars experience sudden increases in luminosity cus of flares or mass ejection events . This group include protostars , Wolf @-@ Rayet stars , and flare stars , as well as bigass and supergiant stars .