Other forms: asterisms
An asterism is a pattern of stars in the dark night sky. One of the most familiar asterisms in the Northern Hemisphere is the Big Dipper, within the constellation Ursa Major.
Like constellations, asterisms are arrangements of stars that form distinct shapes when viewed from Earth. But while constellations are officially recognized by the International Astronomical Union, asterisms can be any pattern of stars at all. Orion is a constellation, but Orion's Belt, which cuts across the middle of it, is an asterism. The Greek root of asterism is aster, "star." The word also refers to a luminous, starlike effect seen in certain gemstones like sapphires, and to a triangular print symbol of three asterisks (⁂), which resemble stars.