Classifying Stars
Brightness as viewed from Earth
Apparent magnitude
Interstellar clumps of dust and gas
Nebula
When gravity balances internal pressure
Main-sequence star
Collection of dust, gas, and stars bound by gravity
Galaxy
Bright pulsating stars used by Hubble
Cepheid Variable Star
True brightness regardless of distance
Luminosity (absolute magnitude)
Large expanded form of a red giant
Supergiant
Star that expands after core hydrogen runs out
Red giant
Thin flat disk with central bulge
Spiral galaxy
Study of the origin and fate of the universe
Cosmology
Diagram plotting luminosity vs temperature
H-R diagram
White dwarf core surrounded by expanding gas
Planetary nebula
Extremely dense remnant made mostly of neutral particles
Neutron star
Oval shaped galaxy
Elliptical galaxy
Theory that the universe began hot and dense and is still expanding
Big Bang Theory
Line where 90% of stars lie (blue to red)
Main sequence
Extremely hot dense star supported by electron pressure
White dwarf
Spinning neutron star that emits radio waves
Pulsar
Galaxy with no obvious symmetry
Irregular galaxy
Light remnant from the Big Bang
Cosmic Microwave Background
Extremely large luminous red stars
Red giants (or supergiants)
Collapse of a massive star that releases huge energy
Supernova
Object so massive that light cannot escape
Black hole
Group of galaxies that may collide
Galaxy cluster
Hypothesized force causing the universe to expand faster
Dark Energy