Stars & constellations · Science & history
Constellations and asterisms
A constellation is an area of sky. The patterns drawn inside it are how people remember it.
Regions, figures and patterns
The International Astronomical Union (opens in a new tab) agreed a list of 88 constellations in 1922 and fixed their boundaries in 1928, so that together they cover the whole sky. It defines no stick figures: the lines on this site's charts are its own drawing, following common Western practice, and other cultures group the same stars differently or use the dark spaces between them.
When the finder says a constellation's key pattern is up, it means the few bright anchor stars listed for it are above the horizon, not that its whole official area is.
Constellation guides
Asterisms
Asterisms (opens in a new tab) are familiar star patterns that are not constellations. Some sit inside one, some straddle several.