Galaxies
Star Life Cycle
Theories of the Universe
HR Diagram
100
Galaxies are classified by their...
Shape
100
Our star the Sun has a mass that is consider to be ________.
Low mass
100
This theory of the universe proposes that everything in the universe started from a super tiny, super hot point. Called a singularity.
The Big Bang
100
What two characteristics are compared on an HR diagram?
Temperature and luminosity
200
Our galaxy the milky way is considered to be this type of galaxy.
Spiral Galaxy
200
A stars lifespan is determined by its...
MASS
200
This theory imagines the universe in a constant cycle of expansion (growing) and contraction (shrinking)
Oscillating Universe Theory
200
A. a star that is hot and has great luminosity
300
What type of galaxy is shown? How do you know?
Irregular galaxy, it has no distinct shape
300
At the end of their life, what celestial objects do small/average sun-like stars leave behind?
White dwarfs
300
This theory suggests that the universe has always been the same and always will be, and as the universe expands, new matter is filling in the gaps.
Steady State Theory
300
According to the HR Diagram below, what is the temperature and luminosity of the Sun.
Temperature: 5,000K
Luminosity: 1
400
What is the shape of an Elliptical galaxy and what type of stars does this galaxy have.
Shape: Oval
Star Type: Old Stars
400
What three stages do all stars go through in their lifetime?
Nebula, Protostar, Main Sequence
400
What is a scientific theory?
A scientific theory is an explanation of why or how something happens in the natural world. It’s based on observations, experiments, and evidence.
400
What type of star has a temperature of 20,000 K and a luminosity of 10-2.
White Dwarf
500
What are the three types of galaxies?
Elliptical, Spiral, and Irregular
500
Most stars spend billions of years in this stage (Hint: the sun is currently in this stage)
Main Sequence
500
What is a scientific law?
A scientific law describes what happens under certain conditions in the natural world. It’s usually a simple statement or equation that shows a consistent pattern.
500
What group of stars has the coolest and brightest stars?
Red Supergiants
600
Position B
600
Energy is released in stars by ____________________.
Nuclear Fusion
600
As galaxies are moving away from us, the light from these galaxies turns red as it stretches out. This is known as the...
Red shift
600
A star with a temperature of 6,500K falls under which spectral class?
Spectral Class: F
700
What do all three galaxies have in common?
They are made up of dust and gas, contain stars, contain planets, and are bound together by gravity
700
Why will the sun never become a black hole?
It is a low mass star!!
700
What evidence supports the theory of an expanding universe? Select TWO correct answers.
1. Light from a distant galaxy shifts to red.
2. Light from a distant galaxy shifts to blue.
3. Wavelength of a distant galaxy becomes longer.
4. Wavelength of a distant galaxy becomes shorter.
1. Light from a distant galaxy shift to red.
3. Wavelength of a distant galaxy becomes longer.
700
This star is 10,000 times brighter than the sun and has a temperature of 5,500. What is the name of this star? 
Polaris