Distance
Stars moving toward us show this spectral shift
blue shift
90% of stars fall on this diagonal
Main Sequence
apparent shift of objects against a distant background due to observer's point of view changing
parallax
The closest star to the sun
Proxima centauri
Hottest spectral class based on temperature
O stars
Stars that are very distant have a ______ parallax. (Large or small)
Small
Where large, hot stars are found on HR diagram
top, left
the actual amount of energy emitted from a star
Absolute magnitude/Absolute brightness/Luminosity
Star with greatest apparent brightness
sun
Coolest spectral class based on temperatures
M stars
A star that has a parallax of 0.1" is this distance from the sun.
1/0.1"=10 parsecs
Where small, cool stars are found of the HR diagram
bottom right
Parsec (pc)
2nd closest star to sun
Barnard's star
If a stars distance is quadrupled, how much dimmer does it appear? (Use inverse square law)
42=16 times dimmer
A star that is 5 parsecs aways from the sun would be _________ lightyears from the sun.
5 x 3.3 = 16.5 ly
Where 1% of stars are found on HR diagram
Bottom, left (white dwarfs)
Star 100x-1000x the radius of sun
Supergiant
Brightest star in our night sky
Sirius
Stars that appear to rotate around each other and are held together by gravity that we can actually see as separate stars.
Visual binaries
The most distant stars have to use _______ parallax to find distance.
spectroscopic
Hottest color of stars
blue
Star equal to or smaller than sun
dwarf
Our sun is this type of star
Yellow dwarf (on the main sequence)
Using luminosity classes Ia-V, what class are brightest supergiants
Ia