|STARS DO NOT LIVE FROEVER. A
time comes when the supply of hydrogen dwindles and the nuclear reactions in the core die
down. but instead of fading away, the star now balloons out to become a brilliant red
giant maybe a hundred times its former diameter. More massive stars become powerful
supergiants, bright enough to be seen across intergalactic space. This transformation
happens because, deep within its core, the star has tapped a new source of energy, helium,
which can keep it shining for a while longer.