| A | B |
|---|
| light-year | distance light travels in a year |
| eclipsing binary star | become dimmer at regular intervals |
| Nuclear Fusion | when a star is born |
| electromagnetic spectrum | all the different types of electromagnetic waves |
| elliptical galaxies | have almost no dust or gas between stars |
| Hubble's Law | farther galaxy is from us, faster it is moving |
| classify stars | size, temperature, brightness |
| supernova | explosion of dying high-mass star |
| gravity | force that pulls together matter in stars |
| H-R diagram | shows that main sequence stars increase in brightness and temperature at same time |
| wobble | indication that planet may exist near distant star |
| lifetime of star | depends on its mass |
| coolest stars | are red |
| black hole | formed when most massive stars collapse |
| parallax | determine star's distance from Earth |
| open cluster | loose grouping of a few thousand stars |
| spectrum | range of colors formed when white light passes through a prism |
| absolute brightness | size and temperture of star |
| Scientific Notation | use powers of ten to write very large or small numbers in shorter form |
| reflecting telescope | has a mirror but no objective lens |
| irregular galaxy | does not have a regular shape |
| radio telescope | detects radio waves from objects in space |
| wavelength | distance between crest on one wave and crest on the next wave |
| spiral galaxy | pinwheel shaped galaxy |
| spectrograph | helps astronomers determine chemical compostion of stars |
