asterism

noun

as·​ter·​ism ˈa-stə-ˌri-zəm 

1

a

: a group of stars that form a pattern in the night sky

On October evenings, when the trees have shed their leaves and stars become visible through the twigs, our best-known asterism, the Big Dipper, passes under the north pole.

—George Lovi

Note: The term asterism does not now usually refer to a constellation but to a star pattern that makes up part of a constellation or that includes stars from more than one constellation.

b

: a small group of stars

2

: a star-shaped figure exhibited by some crystals by reflected light (as in a star sapphire) or by transmitted light (as in some mica)

Examples of asterism in a Sentence

Recent Examples on the Web

Moon Nears Pleiades November and December are the best months to see the Pleiades star cluster, a shimmery asterism of more than 1,000 stars. —Stephanie Vermillion, Travel + Leisure, 2 Dec. 2024

Find the other two that make up the famous asterism — Deneb in Cygnus, above Vega, and Altair in Aquila, to the left. —Jamie Carter, Forbes, 1 Nov. 2024

This asterism, located within the Taurus constellation, is a fan favorite among stargazers. —Stephanie Vermillion, Travel + Leisure, 1 Feb. 2024

Also during evening hours this month, three bright stars form an asterism known as the summer triangle. —Geoff Chester, Washington Post, 1 Sep. 2023

Word History

Etymology

borrowed from Greek asterísmos, from asterízein "to arrange in constellations" (from aster-, astḗr "star" + -izein -ize) + -ismos -ism — more at star entry 1

First Known Use

1598, in the meaning defined at sense 1a