Vocab Flashcards
(29 cards)
Doppler shift
The shift to a different wavelength.
Spiral galaxy
A galaxy exhibiting a central nucleus from which extend curved arms of higher luminosity.
Supernova
An enormous explosion that destroys a star.
Dark energy
An invisible form of energy that creates a repulsive force causing the universe to expand.
Hertzsprung- Russell Diagram
A graph that plots luminosity v. temperature of stars.
Neutron star
Super bright, dense star left over from a supernova.
Giant Star
A star with a much larger radius and luminosity than a main sequence star of the same surface temperature.
Black hole
An area in space that is so dense that nothing, including light, can escape its gravitational pull.
Light-year
The distance light travels in one year.
Luminosity
It is the true brightness of a object.
Main sequence star
A star that fuses hydrogen into helium in its core.
Irregular galaxy
A galaxy with no identifiable shape or structure.
White dwarf
Forms as the core of a giant star no longer supports fusion and the star’s outer layers escape into space, leaving a hot and dense core.
Absolute magnitude
Measures the brightness of a star based on the temperature and mass.
Galaxy
A huge collection of stars, gas, and dust.
Nebula
A cloud of gas and dust.
Apparent magnitude
The measure of how bright the star appears from Earth.
Cosmic background radiation
Leftover energy from the Big Bang.
Elliptical galaxy
A galaxy that has a generally elliptical shape and that has no apparent internal structure or spiral arms
Planetary nebula
Formed after helium in a star’s core is gone, it casts off its gases.
Big Bang Theory
The theory that the universe began as a point and has been expanding ever since.
Universe
All of space and everything in it including stars, planets, and galaxies.
Milky Way galaxy
The spiral galaxy of which the Sun and the solar system are a part.
Supergiant
A high mass star toward the end of its life that is running out of hydrogen to fuse into helium.
