Chapter 16 - Space Flashcards
Big Bang Theory
The theory that the universe was created in a massive explosion, and that the universe has been expanding ever since.
Black dwarf
A star that has faded out and gone cold
Black hole
An object in space that has so much mass that nothing, not even light, can escape from its gravitational field.
Centripetal force
The resultant force towards the centre of a circle acting on an object acting in a circular path.
Cosmic microwave background radiation (CMBR)
Electromagnetic radiation that has been travelling through space ever since it was created shortly after the Big Bang.
Dark matter
Matter in a galaxy that cannot be seen. Its presence is deduced because galaxies would spin much faster if their stars were their only matter.
Main sequence
The main sequence is the life stage of a star during which it radiates energy because of fusion of hydrogen nuclei in its core
Neutron star
The highly compressed core of a massive star that remains after a supernova explosion.
Red giant
A star that has expanded and cooled, resulting in it becoming red and much larger and cooler that it was before it expanded.
Red supergiant.
A star much more massive than the Sun will swell out after the main sequence stage to become a red supergiant before it collapses.
Redshift
Increase in the wavelength of electromagnetic waves emitted by a star or galaxy due to its motion away from us. The faster the speed of a star or galaxy, the greater the redshift is.
Protostar
The concentration of dust clouds and gas in space that forms a star.
Supernova
The explosion of a massive star after fusion in its core ceases and the matter surrounding its core collapses onto the core and rebounds.
White dwarf
A star that has collapsed for the red giant stage to become much hotter and denser.
