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

Having dominated the winter sky for months, the reign of this bright asterism is now coming to an end. —Jamie Carter, Forbes, 24 Mar. 2025

Although Ursa Major is well known, few stargazers can go beyond the core asterism — the Big Dipper. —Jamie Carter, Forbes, 17 Mar. 2025

For example, Rankin said the moon right next to the Big Dipper asterism is a sure sign of fakery. —Robert Lea, Space.com, 13 Mar. 2025

Procyon, Sirius and Betelgeuse in Orion form the Winter Triangle asterism that is easy to see even from light-polluted locations in cities and suburbs. —Jesse Emspak, Space.com, 27 Dec. 2024

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

Rhymes for asterism

• autism
• fascism
• racism
• sikhism
• statism
• sufism
• thomism
• tourism
• tropism
• abolitionism
• aldosteronism
• americanism