Sun/Stars
What created the universe?
Big Bang
What is a galaxy?
A galaxy is a huge group of stars, nebulae, dust, gas, planets, etc that stay near each other because of gravity.
Where do all stars begin?
Stellar Nebula
What is the force that is constantly trying to keep the universe together?
Gravity
How many stars does a typical galaxy contain?
About 100 billion stars.
What causes stars to have different life cycles after main sequence stage?
their MASS
Why does nuclear fusion occur?
Friction and heat build up in a protostar.
How much of the universe is made of:
Regular matter?
Dark Matter?
Dark Energy?
4%
27%
68%
Where is our solar system located?
It is located in a spiral arm of the Milky Way Galaxy (a spiral galaxy), about half way out from the center.
What is the full life cycle of our sun?
nebula, protostar, main sequence, red giant, white dwarf, black dwarf.
Where is the Sun in it’s life cycle?
About half way through the main sequence stage of its existence.
How old is the Universe? And how long is a "month" and a "day" on the cosmic calendar?
over 13 billion years.
over 1 billion
over 40 million
What are the four types of galaxies?
Spiral (barred and regular), Elliptical, and Irregular
What is the life cycle of a high mass star?
nebula, protostar, main sequence, supernova, neutron star
What elements does the Sun and all stars use and create in nuclear fusion?
The Sun fuses hydrogen to form helium.
What are the three theories of universe behavior? Which one is discredited?
1. expanding forever.
2. will eventually reach equilibrium (discredited)
3. Will eventually shrink back.
What is the current behavior of galaxies in our universe? why?
They are moving away from each other.
What was originally at the center of the Milky Way?
a Very Massive Star