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

Together, these stars form a famous asterism known as the Summer Triangle. —Anthony Wood, Space.com, 11 May 2026

Called an asterism, which is a prominent group of stars that form a noticeable pattern, the celestial arrangement is a wintertime phenomenon in the Northern Hemisphere. —Michele Laufik, Martha Stewart, 9 Feb. 2026

Visible on clear September evenings, this seven-star asterism (a shape of stars, not an official constellation) moves into a noticeably low position in the northern sky after sunset. —Jamie Carter, Forbes.com, 16 Sep. 2025

The Big Dipper, part of Ursa Major, is another prominent asterism. —Hana Al-Khodairi, Condé Nast Traveler, 17 June 2025

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
• sophism
• statism
• sufism
• thomism
• tourism
• tropism
• abolitionism
• aldosteronism