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The Life Cycle of a Star. Nebula. Giant clouds of gas and dust The birthplace of stars!. Eagle Nebula: 9.5 Light Years Tall!. http://hubblesite.org/gallery/tours/tour-m16/. Creation of a Star.
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Nebula • Giant clouds of gas and dust • The birthplace of stars!
Eagle Nebula: 9.5 Light Years Tall! http://hubblesite.org/gallery/tours/tour-m16/
Creation of a Star • Hydrogen gas is pulled together by gravity. It begins to spin, heats up, and becomes a star.
Cool Fact: Hydrogen in its core is converted into helium– this creates massive amounts of heat and light energy (this is called nuclear fusion)
Average Stars (such as our sun) • Lifetime: Approximately 9 billion years • Converts hydrogen into helium (nuclear fusion) • Medium size, medium temperature
Hydrogen runs out. Outer layers of the star cool and expand outward • Red Giant – cool, large, red star running out of fuel • Cool Fact: When this happens to our Sun, scientists hypothesize that it will extend out as far as the Earth or even Mars.
Core of the Red Giant collapses • Outer layers drift away • White Dwarf – Small, dense star • Cool Fact: Typically, a white dwarf has a radius equal to about 0.01 times that of the Sun, but it has a mass roughly equal to the Sun's. This gives a white dwarf a density about 1 million times that of water!
White dwarf runs out of energy, cools and dies • Black Dwarf – small, dead star
Path #2: Massive Stars! • Lifetime = approximately 10 million years • Size = 10-1000 times the size of the Sun! • Converts hydrogen to helium much quicker
Hydrogen runs out very quickly. • Outer layers of the star cool and expand outward • Red Super Giant – Very large, cool, red star • Continues to burn and expand to a larger volume
They continue to burn for a time and expands to an even larger volume.
When a star dies, it explodes into a radioactive cloud. • Supernova • Extremely bright explosion • Brighter than an entire galaxy! • Kepler’s Supernova
Cassiopeia A (Cas A, for short), the youngest supernova remnant in the Milky Way.
Leftovers of a supernova. • Neutron Star/Pulsar: • 20 km • Super small, super dense • Collapsed middle of a giant star • If it starts spinning, this is a pulsar • Cool Fact: According to astronomer and author Frank Shu, "A sugar cube of neutron-star stuff on Earth would weigh as much as all of humanity!" Neutron stars can be observed as pulsars.
Core of a more massive star collapses into a very small space • Gravity becomes so strong not even light can escape, creating a black hole • Video: Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background
Cool Picture: This is a simulated view of a black hole in front of the Large Magellanic Cloud. • http://commons.wikimedia.org/wiki/File:BH_LMC.png