The coldest stars are considered to be what color?
Red
What is luminosity?
luminosity is apparent magnitude - the brightness of an object as it appears from earth

Which the dimmest?
Proxima Centauri
As you move towards the right of the H-R diagram, stars become....
cooler
The hottest stars are considered to be what color?
Blue
What are the largest stars called?
Red Supergiants

Find a star that has a higher absolute magnitude than betelgeuse
Rigel, Deneb, RW Cephei, Canopus
As you move down the H-R diagram, stars become...
more dim
What is the name of the portion of the H-R diagram where most of the stars reside?
+100 for the percentage
Main Sequence
90%
If a star were to increase in absolute magnitude, what direction would the star move on the H-R diagram?
up
Find a star with a lower effective temperature than our sun
Barnard's Star, Proxima Centauri, Aldebaran, Mira, Antares, Betelgeuse
As you towards the left of the H-R diagram, what increases (only left, not up)
temperature (and mass)
What are the main 2 variables used to plot stars on the H-R diagram?
Absolute brightness (Luminosity) Temperature,
There are 3 stars of equal size and equal apparent brightness, however they are located at various distances. One star is blue, one is yellow, and one is red. Order them from least to greatest based on absolute magnitude.
Red, Yellow, Blue

Compare the luminosity between Sirius B, The Sun, and Rigel
Sirius B is the least luminous of the 3, The sun is more luminous than Sirius B, Rigel is the most luminous of the 3
Stars produce energy via....
Nuclear Fusion
Describe where stars move as they age?
x2 for what traits change
They move up and to the right.
They become larger, brighter, but cooler.
There are three stars a,b, & c located at the same distance from Earth. Star B has a high temperature and is a white star, star A is by far the biggest and is a red giant, and star C is the smallest but the hottest being a white dwarf. Order the stars based on their apparent brightness.
Star A, B, C
Which types of stars are the most dense, which are the least?
Most: White Dwarfs
Least: Red Hypergiants
As you move from bottom left corner to top right corner, what decreases?
Density