| A | B |
|---|
| nebula | A large amout of gas and dust in space spread out in an immense volume |
| protostar | A contracting cloud of gas and dust; the earliest stage of a star's life |
| Wave length | The horizontal distance between two wave crests |
| Convex Lens | A piece of transparent glass current so that the middle is thicker than the edges |
| spectrorn | The range of wavelenths of eletromagnet waves |
| Main Sequence | An area on the Hertzspring Russell diagram that runsfrom the upper left to the lower right and includes more than 90 percent of all stars |
| Refracting telescope | A telescope that uses conexlens togather and focus light |
| neutron star | A tiny star that remains after a supernova explosion |
| Parallax | The apparent change in posistion of an object when seen from different places |
| Quasar | A distant galaxy with a blakehole at itys center |
| Black Hole | The remains of an extremely massive star pulled into a small volume by the force of gravity |
| Pulsar | A neutron that poduces radio waves |
| Electromagnet rotation | Energy that travels through space in the form of waves |
| Galaxy | A giant structure that contain hundreds of billions of stars |
| Giant star | A very large star, much larger that the sun |
| apparent magnitude | the brightnesss of a star as seen from Earth |
| Absolute magnitude | the brightness of a star if it were a standerd distance from Earth |
| eclipsing binary | a star system in which one star periodically Blocksthe light from another |
| supernova | the explosion of a dying giant or super giant star |
| visible light | Electromagnetic radiation |
