Life cycle of a star

Life Cycle of a Star Waves, Atoms and Space Stage 1 Protostars Protostars • Huge clouds of gas (hydrogen) in which stars are made. • Many thousands of times bigger than our solar system • As the clouds collapse stars are born in them Stage 2 Main sequence star Main Sequence Star • E.g. Our sun • Sequence lasts for about 10 000 million years • Our sun is about half way through it’s main sequence Stage 3 Red Giant Red Giant • As the sun runs out of hydrogen the outer layers of the sun will become cooler • They will also expand massively. • The Earth (along with Mercury, Venus and Mars) will be swallowed up. Stage 4 White Dwarf White Dwarf • Gravity will cause the red giant to collapse • The sun is now much cooler and it collapses into a small white star • It still has the same mass as the original sun! Stage 5 Black Dwarf Black Dwarf • The sun cools more and more • Eventually it will become a black mass emitting no light • It will then spend the rest of eternity drifting silently through space Stars bigger than our sun! At least four times bigger (you don’t need to know about these for your exams) Stage 4 (for a big star) Red Supergiant Stage 5 (for a big star) Supernova Supernova! • The largest and most powerful explosions in the universe. • The red supergiants literally blow themselves apart! Supernova • All the atoms we are made from came originally from these giant supernova explosions. Stage 6 (for a big star) Black hole Black hole • After the supernova a huge mass is left behind. • There is so much mass its gravity prevents even light from leaving it • Black holes can suck in nearby stars and solar systems. • Luckily there are no black holes any where near our sun!