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

"We were stunned to see how asymmetric this disk is," said co-investigator Joshua Bennett Lovell, also an astronomer at the CfA.

From Science Daily • May 12, 2026

In the 1890s, long-simmering dreams of an inhabited Mars found a foothold in the U.S., fanned by wealthy astronomer Percival Lowell, who built an Arizona observatory.

From The Wall Street Journal • Apr. 23, 2026

Roman, which took more than $4 billion and over a decade to build, is named after astronomer Nancy Grace Roman, nicknamed the "Mother of Hubble" for her role in developing the landmark space telescope.

From Barron's • Apr. 22, 2026

The astronomer who discovered what stars are made of, Cecilia Payne-Gaposchkin, has been commemorated with an English Heritage blue plaque at her teenage home, 70 Lansdowne Road in Notting Hill.

From BBC • Apr. 22, 2026

There might be philosophical reasons for preferring one to the other, but an astronomer could happily use either to perform calculations.

From "The Invention of Science" by David Wootton

Related Words

• astrophysicist
• cosmologist