Chapter 2 & 3 Space Flashcards
How big is a galaxy?
They range in size.
What is a galaxy?
Made of 100 million to 1 trillion stars, gas and dust held together by gravity
What is a light year?
The distance that light travels in a year
What is luminosity?
Actual brightness of a star
How can you determine the temperature of a star?
Stars with cool surfaces are red and hotter stars are blue
Does the sun move?
Yes, it rotates on an axis like Earth.
How long does the sun to rotate?
It takes about 35 days.
Nuclear Fusion
When the sun produces energy
Sunspots
Dark areas that form on the surface of the sun
Solar flare
An explosive release of energy that can expand outward as far as the Sun’s outer atmosphere
Prominences
Huge loops of relatively cool gas
Gravity
A force of attraction between objects
Orbit
The path the a body follows as it travels around another body and n space
Aphelion
An object is farthest from the sun
Perihelion
An object is closest to the sun
