Definition of asterism
1a : 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 ◆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)
Recent Examples of asterism from the Web
Many constellations display unique geometrical shapes and asterisms.
As the days go on in February, the comet will quickly make a loop around the distinct Circlet asterism, a star pattern nestled within the constellation Pisces, the fishes.
In this case the asterism is made up of stars from the constellations Libra, Virgo, Centaurus, and Triangulum Australe.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'asterism.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of asterism
Greek asterismos, from asterizein to arrange in constellations, from aster-, astēr
First Known Use: 1598See Words from the same year
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