430 likes | 571 Vues
Life Cycle of a Star. Waves, Atoms and Space. Black Dwarf. 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.
E N D
Life Cycle of a Star Waves, Atoms and Space Black Dwarf
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 • Burning Hydrogen • 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.
Planetary Nebula • Following the Red Giant Stage • (a) Planetary Nebula (gas) • (b) White Dwarf
Stage 4 White Dwarf The car engine is turned off … Hood is still hot
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
When the core is trying to fuse Fe No more energy can be gained Fusion stops, no more outward pressure Gravity Wins … the collapse starts After the collapse … rebound … material explodes out Heavy elements formed during these final stages
Supernova! • The largest and most powerful explosions in the universe. • The red supergiants literally blow themselves apart!
Supernova • All the heavy atoms made from came originally from these giant supernova explosions.
Stage 6(for a big star … after the rebound) 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.
Supermassive Black Holes A supermassive black hole (SMBH) is the largest type of black hole, on the order of hundreds of thousands to billions of solar masses. Most—and possibly all—galaxies are inferred to contain a supermassive black hole at their centers. In the case of the Milky Way, the SMBH is believed to correspond with the location of Sagittarius A* Video Clip
Neutron Stars A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type (II) event. Such stars are composed almost entirely of neutrons, which are subatomic particles without net electrical charge and with slightly larger mass than protons Neutron Star Formation