Unit 6 Universe Vocab Flashcards
Apparent magnitude
The brightness of a star as seen from earth
Big Bang theory
The theory that all matter and energy in the universe was compressed into an extremely small volume that 13-15 billion years ago exploded and began expanding in all directions
Cosmic microwave background(CMB)
The electromagnetic radiation left over from the formation of the universe
Doppler effect
An observed change in frequency or wavelength when the source is moving with respect to the observer
Electromagnetic spectrum
All of the different wavelengths and frequencies of electromagnetic radiation, from radio waves to gamma rays
Galaxy
A collection of stars, dust, and gas bound together by gravity
H-R diagram (Hertzsprung- Russell diagram)
A graph that shows the relationship between a stars surface temperature and absolute magnitude
Light year
The distance that light travels in one year; about 9.46 trillion km
Luminosity
The actual brightness of an object such as a star
Main sequence
The region on the H-R diagram where stars spend most of their lives; it has a diagonal pattern
Nebula
A large cloud of dust and gas in interstellar space; stars are born here
Planet
A relatively large spherical body that orbits a star
Neutron star
The core of a supernova that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons
Pulsar
A highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation
Red shift
A phenomenon which occurs when a star of galaxy is moving away from the earth and its wavelengths emitted are stretched out due to the Doppler effect
Revolution
The motion of a body that travels around another body in space
Rotation
The spin of a body on its axis
Solar system
A collection of large and small bodies that orbit our central star, the sun
Spectroscope
A tool used to collect light from stars and separate the colors in the light
Star
A large celestial body that is composed of gas and emits light; the sun is a typical star
Supernova
A gigantic explosion in which a massive star collapses and throws its outer layers into space, but its core remains
Universe
Space and all the matter and energy in it
Wave length
The distance between two adjacent crests or troughs of a wave
White dwarf
The hot, dense , dim core of matter remains from the collapse of a lowmass star
Spiral galaxy
A galaxy shaped like a pin wheel, with a center bulge and spiral arms extending outwards
Elliptical Galaxy
A spherical or elongated Galaxy with a bright center and very little dust and gas
Irregular Galaxy
A Galaxy with an irregular shape and doesn’t fit in any oh her category
Absolute magnitude
A brightness scale used to measure how bright a star would be if it were seen from a standard distance
