astronomer

American  

[uh-stron-uh-mer] / əˈstrɒn ə mər /

noun

1. an expert in astronomy; a scientific observer of the celestial bodies.

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astronomer British  

/ əˈstrɒnəmə /

noun

1. a scientist who studies astronomy

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Etymology

Origin of astronomer

First recorded in 1325–75; Middle English; see origin at astronomy, -er ¹

Explanation

A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars, is called an astronomer. These days, the terms astronomer and astrophysicist are used interchangeably, to talk about any physicist who specializes in celestial bodies and the forces that affect them. Astronomers use telescopes and cameras to observe the stars and other objects in the sky, and they often use complicated math to make predictions and solve puzzles about their movements and locations. The Greek root, astronomia, literally means "star arrangement."

Example Sentences

If you’re an astronomer, it’s people confusing what you do with astrology.

From Salon • Apr. 14, 2026

A museum has been given a grant to fund a project about a Bradford-born astronomer who was influenced by the work of medieval Islamic scientists.

From BBC • Apr. 1, 2026

The calculation was created in the 1800s by a Belgian astronomer, and then a doctor in the U.S. renamed it the body mass index in the 1970s.

From MarketWatch • Mar. 18, 2026

Nearly a century ago, astronomer Edwin Hubble discovered that almost all galaxies are receding from the Milky Way.

From Science Daily • Mar. 6, 2026

But then a less arrogant individual than Tycho would still have had his nose intact and might never have become such a great astronomer in the first place.

From "The Scientists" by John Gribbin

Related Words

• astrophysicist
• cosmologist