|1.||three asterisks arranged in a triangle (̄⁂ or |
|2.||a starlike effect seen in some minerals and gemstones when viewed by reflected or transmitted light|
|3.||a cluster of stars, which may be a subset or a superset of a constellation|
|[C16: from Greek asterismos arrangement of constellations, from astēr star]|
|asterism (ās'tə-rĭz'əm) Pronunciation Key
A conspicuous star pattern that is not recognized as a constellation. Asterisms may constitute a part of a larger constellation, as in the case of the seven stars in Ursa Major that make up the Big Dipper, or they may be formed of individual stars in several different constellations, as in the case of the Summer Triangle, made up of Deneb (in Cygnus), Altair (in Aquila), and Vega (in Lyra).