Properties of Stars

Luminosity

Quantifiable measure of the brightness of an object — expressed as a fixed value, and accepted as an intrinsic property of the source.

Apparent Brightness

Tells us how bright a light source appears to a given observer. Changes with distance between the observer and source.

Parallax

A measure of approximate distance that measures shifts in approximate position between different vantage points.

Inverse Square Law of Light

The amount of light received from a source drops off with the square of distance. We receive a larger fraction of light emitted by a closer source, so it has a higher apparent brightness.