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Part 3
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A star is an object in space made up of hot
gases, with a core that is like a thermonuclear
reactor.
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Forms from the materials in a nebula when
gravity starts acting on chunks of gas and dust,
pulling them together.
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As gravity keeps working, the mass grows and
the material collapses in on itself and contracts.
An early phase of star, called a “protostar,”
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Low mass stars
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these stars start small
exist that way for most of their life as dim, cool red
dwarfs.
burn their hydrogen fuel very slowly 100 billion
years.
Die as hot dim white dwarfs and quietly burn out.
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Intermediate mass stars ( the Sun)
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star lasts only about 10 billion years.
long period of stability
expands into a red giant.
slowly shrinking into a small, dim white dwarf.
it cools into a black dwarf, a dense, dark body made
up mostly of carbon and oxygen.
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High mass stars
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12 or more times the mass of the Sun
consume their fuel faster than smaller stars
Become red giants. (supergiants)
last for only 7 billion years.
they collapse in on themselves causing a massive
explosion called a supernova.
the remaining core of the supernova will eventually
collapse to form a neutron star. A sphere only 10 km
wide.
High mass stars
Star
Relative Size
Vega
2.135
Canopus
8.5
Sun
1
Arcturus
1.1
Betelgeuse
18-19
Rigel
17
Delta Orionis
20