| A | B |
|---|
| constellation | a pattern of stars in the sky |
| radio telescope | a device used to detect radio waves from objects in space |
| observatory | a building that contains one or more telescopes |
| spectrograph | an instrument that seperates light into colors and photographs the resulting spectrum |
| pulsar | a neutron star that produces radio waves |
| nebula | a large amount of gas and dust in space, spread out in an immense volume |
| white dwarf | the remaining hot core of a star after its outer layers have expanded and drifted out into space |
| supernova | the explosion of a giant or supergiant star |
| protostar | a contracting cloud of gas and dust; the earliest stage of a star's life |
| neutron star | a tiny star that remains after an explosion |
| quasar | a distant galaxy with a black hole at its center |
| black hole | the remains of an extremely massive star pulled into a small volume by the force of gravity |
| galaxy | a giant structure that contains hundreds of billions of stars |
| universe | all of space and everything in it |
| light-year | the distance that light travels in one year |
| parallax | the apparent change in position of an object when seen from different places |
| giant star | a very large star, much larger than the sun |
| apparent magnitude | the brightness of a star as seen from earth |
| absolute magnitude | the brightness of a star if it were a standard distance from earth |
| main sequence | an area on the Hertzsprung-Russell diagram that runs from the upper left to the lower right and includes more than 90% of all stars |
| Hertzsprung-Russell diagram | a graph relating the temperature and brightness of stars |
| binary star | a star system that contains two stars |
| eclipsing binary | a star system in which one star periodically blocks the light from another |
| spiral galaxy | a galaxy whose arms curve outward in a pinwill pattern |
| elliptical galaxy | a galaxy shaped like a flattened ball, containg only old stars |
| irregular galaxy | a galaxy that doesn't have a regular shape |
| Big Bang | the initial explosion that resulted in the formation and expansion of the universe |
