Unit 7 Vocabulary
Universe Space and everything that exists within it including all matter and energy
Galaxy A collection of stars, gas, dust and other objects bound together by gravity
Star A large body of gas which is held together by gravity and emits light and energy through nuclear fusion
Nebulae clouds of dust and gas; site of star formation; remains of dead or dying stars
Main Sequence Star A stable star which is actively fusing hydrogen and is shown in a diagonal pattern within a H-R diagram
Absolute Magnitude a measure of how bright a star really is, if all stars were the same distance from Earth
Apparent Magnitude a measure of how bright a star appears as seen from Earth
Hertzsprung-Russell Diagram a graph that shows the relationship between the brightness, surface temperature, and color of stars
Luminosity total amount of light (energy) emitted by a star or other celestial body
Spectroscope A tool for analyzing light; used to determine the elements present in the light source
Spectra different colors of light emitted based on the chemical composition of the light source
Electromagnetic Spectrum a classification of all forms of radiation by wavelength and frequency; used to study components of the universe
Electromagnetic Wave A wave of electricity and magnetism that travels at the speed of light
Wavelength The distance between any point on a wave to the same point on the next cycle of the wave
Frequency the number of times a wave passes a certain point in a given amount of time
Big Bang Theory a current scientific theory concerning the early development of the universe from a dense state which began and is still expanding