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From birth … to death…. Star Life Cycle. Nebula. A huge cloud of dust and gas (mostly hydrogen) pulled together by gravity Called the “birthplace of a star” Theory is that the dust came from the explosions of other stars. Nebulae Examples…. Protostar.
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From birth… to death… Star Life Cycle
Nebula • A huge cloud of dust and gas (mostly hydrogen) pulled together by gravity • Called the “birthplace of a star” • Theory is that the dust came from the explosions of other stars
Protostar • Gravity causes the particles of gas and dust to move together • Temperature and pressure increase and the cloud begins to spin
Star • The protostar continues to contract due to gravity • Temperature and pressure continue to increase • When temperature reaches 10 million degrees Celsius, nuclear fusion begins
Nuclear Fusion • At temperatures of 10 to 15 million degrees Celsius, nuclear fusion occurs in stars • Hydrogen are converted into one helium plus a lot of energy!
Star Death • Death is determined by mass. When the last of helium atoms in the core are fused into carbon atoms, the star begins to die. • A sun-sized star will first expand to a red giant, then collapse on itself to become a white dwarf.
Massive Star Death • Energy is released in a powerful explosion called a supernova • It then becomes a neutron star. No nuclear fusion is taking place to support the core, so it is swallowed by its own gravity.
Black Holes Only a very massive star can become a black hole, which is not visible and is so dense nothing can escape.
Some media • http://science.discovery.com/video-topics/space-videos/supermassive-black-holes-the-black-hole.htm • http://www.space.com/15421-black-holes-facts-formation-discovery-sdcmp.html