lives of stars chapter 17 section 4 pages 583-589 chapter 17 section 4 pages 583-589
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Lives of Stars
Lives of Stars
Chapter 17 Section 4
Pages 583-589
Chapter 17 Section 4
Pages 583-589
Life Cycle of Stars
• 1. Nebula- A star nursery (gases and dust)– Gravity pulls gas and dust
together.
• 2. Protostar (earliest)– Star is born when nuclear
fusion starts. (combining hydrogen into Helium. Releases large amounts of energy.
Birth of a Star
• Determined By Mass!1.Large Stars- Short lives (10 million)
2.Medium Stars- (10 billion)1. The sun 4.6 Billion Years old
3.Small Stars- Long Lives (200 billion)
Life Time of Stars
1.Occurs when a star begins to run out of fuel.
2.All stars become a giant or a super giant depending on their mass.
3.The final fate of a star is determined by mass.
Death of Stars
• Small Medium Stars
• Were once red giants that lost their atmosphere
• A glowing white core remains– About the size of Earth– 1 million times denser than the
sun
• When it stops glowing, it’s dead, becomes a black dwarf.
White Dwarfs
• When a giant or supergiant star suddenly explodes.
• Must be a massive star.
• Gases expelled can become a new star.
Super Nova
• Left by a Supernova.
• When a giant or super giant star explodes.
• Smaller than white dwarfs
• Extremely Dense
• Pulsar- spinning neutron stars that give off radio waves.
Neutron Stars
• Occurs after the most massive stars explode.
• Gravity PULLS gasses into a small place.
• Gravity becomes so great that nothing not even light can escape.
Black Hole
• Very bright objects, but far away. 12 billion light years
• Very distant galaxies with very massive black holes in the center.
• The gases around the black hole heat up and shine brightly.
Quasars
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