| A | B |
|---|
| solar system | small and large bodies orbiting the central star, our sun |
| planet | spherical body that orbits the sun |
| star | large celestial body - composed of gas and emits light refers to a |
| galaxy | large collection of stars, gas and dust all held together by gravity |
| light-year | distance measured in light as it travels through space within one year |
| universe | space and all matter and energy found in it |
| luminosity | actual brightness of a star |
| apparent magnitude | measurement of a star's brightness as we see it from Earth |
| absolute magnitude | measurement of a star's brightness if the star was located at a standard distance |
