What is the difference between a constellation and an asterism?

Constellations and asterisms are terms used to describe patterns of stars in the sky, but there are some important differences between the two.

A constellation is an officially recognized area of the sky that contains a specific pattern of stars. There are 88 constellations recognized by the International Astronomical Union, and they are used to divide the sky into specific regions. Each constellation has its own name and history, and they are often associated with mythological figures or animals.

An asterism, on the other hand, is a recognizable pattern of stars that is not an official constellation. Asterisms are often smaller and less distinct than constellations, and they are often made up of stars from multiple constellations. Examples of famous asterisms include the Big Dipper and the Summer Triangle.

While constellations are officially recognized and have a specific area of the sky associated with them, asterisms are more informal and can be recognized by anyone who can see the stars.