Chapter 30 Vocab Flashcards
one of 88 regions into which the sky has been divided in order to describe the locations of celestial objects; a group of stars organized in a recognizable pattern.
Constellation
vary in shape, from nearly spherical to very elongated, are extremely bright in the center, and do not have spiral arms.
Elliptical Galaxy
theory that all matter and energy in the universe was compressed into an extremely small volume that 3 to 15 billion years ago exploded and began expanding in all directions.
The Big Bang
radiation uniformly detected from every direction in space; considered a remnant of the big bang.
Cosmic background radiation
has a nucleus of bright stars and flattened arms that spiral around the nucleus.
Spiral galaxy
has no particular shape, and is fairly rich in dust and gas.
Irregular Galaxy
quasi-stellar radio source; a very luminous object that produces energy at a high rate.
Quasar
a rapidly spinning neutron star that emits pulses of radio and optical energy.
Pulsar
a star that suddenly becomes brighter.
Nova
As gravity makes dense regions within a nebula more compact, these regions spin and shrink and begin to form a flattened disk.
Protostar
a large cloud of gas and dust in interstellar space; a region in space where stars are born.
Nebula
Stars moving away from Earth are shifted slightly toward red.
Red shift
a small, hot, dim star that is the leftover center of an old sunlike star.
White dwarf
pairs of stars that revolve around each other and are held together by gravity.
Binary stars
an observed change in the frequency of a wave when the source or observer is moving
Doppler effect
