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16 Cards in this Set

  • Front
  • Back
What is a Star?
An object in space made of burning gasses, which produce their own light and heat.
What is Nuclear Fusion?
The process by which suns produce light and heat (2 Hydrogen atoms combine to form 1 Helium atom)
What are the 3 Types of Stars?
• Main Sequence Stars - hottest and largest generate the most light (Sun)

• White Dwarfs - very hot but not bright

• Giants and Super Giants - extremely bright but not hot
Our Star – The Sun is?
• Age: 4.6 billion years

• Will last another 5 billion year or so

• Type: Main Sequence Star

• Size: medium sized star (large for a medium star)

• Diameter = 1.4 million km

• Composition: 92% Hydrogen and 8% Helium
Layers of the Sun?
• Layers of the Sun
• Core (middle of sun) = 27,000,000 o F
_ Nuclear Fusion: the process by which suns produce light and heat (2 Hydrogen atoms combine to form 1 Helium atom)
• Convection and Radiation Zones: areas where heat produced in the core of the sun rises to the surface
• Photosphere (outer visible layer) = 11,000o F
What is a Galaxy?
A large group of stars, gas and dust held together by gravity.
Who was the First astronomer to classify galaxies by shape?
Edwin Hubble.
What did Edwin Hubble notice.
Noticed that galaxies were spreading apart
• 3 major types of Galaxies
3 Major types of galaxies?
What are Elliptical Galaxies?
Some elliptical galaxies are nearly circular in shape. Some elliptical galaxies are extremely stretched out, flattened,or elongated.
What are Spiral Galaxies?
Galaxies with bright nuclei also had "arms" spiraling out from the middle.
What are Irregular Galaxies?
Galaxies that can't be classified as either spiral or elliptical.
Who noticed The Universe and Big Bang?
• Edwin Hubble
What did he notice?
Noticed galaxies were getting farther apart
o Universe is constantly expanding in all directions
What is the Big Bang Theory?
o 10-20 billion year ago tremendous explosion started expansion of universe from single point.
What is the Copernican Theory?
Universe appears the same in all directions.