| A | B |
|---|
| binary star | member of a double star system |
| constellation | group of stars that make a picture |
| nova | star that suddenly increases in brightness |
| nebula | cloud of dust and gasses ; birthplace of stars |
| galaxy | huge group of stars |
| spiral galaxy | galaxy shaped like a pinwheel |
| elliptical galaxy | oval-shaped galaxy |
| spectroscope | device used to break light into the visible spectrum |
| spectrum | colors of light; ROYGBIV |
| redshift | occurs when a star is moving away from Earth |
| Doppler effect | apparent change in wavelength of light when a star is moving |
| big-bang theory | idea that the universe began with the explosion of concentrated matter and energy |
| gravity | force of attraction between objects |
| quasar | quasi-stellar radio source |
| giant star | star that is 10 to 100 times as large as Earth |
| supergiant star | largest of all stars |
| white dwarf | small dense star |
| neutron star | smallest of all the stars |
| apparent magnitude | brightness of a star as it appears from Earth |
| absolute magnitude | actual brightness of a star |
| Hertzsprung-Russell diagram | chart that compares a star's surface temperature and brightness |
| main-sequence star | stars on the H-R diagram from the upper left to lower right corners |
| parallax | apparent change in a star's position due to Earth's movement |
| nuclear fusion | process of fusing atoms together |
| corona | outermost layer of the sun's atmosphere |
| chromosphere | middle layer of the sun's atmosphere |
| photosphere | inner layer of the sun's atmosphere |
| core | center of the sun |
| prominence | sunstorm in the form of arches or loops |
| solar flare | storm on the sun that appears as a bright burst of light on the surface |
| solar wind | continuous stream of high-energy particles released in all directions from the sun |
| sunspot | dark area on the sun's surface |
| axis | imaginary line on which an object rotates |
| protostar | new star |
| supernova | tremendous explosion in which a star breaks apart |
| pulsar | neutron star that spins and gives off radio waves |
| black hole | core of a supermassive star that remains after a supernova |
