Local Group

American  

noun

Astronomy.

1. the group of galaxies, at least 25 of which are known, that includes the Milky Way.

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Local Group British  

noun

1. astronomy the cluster of galaxies to which our galaxy and the Andromeda Galaxy belong

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Local Group Scientific  

1. A group of more than 30 galaxies that includes 2 large spiral galaxies—the Milky Way and Andromeda—as well as numerous smaller galaxies, many of which are dwarfs. The Local Group has a diameter of approximately 10 million light-years, with its gravitational center located between our galaxy and the Andromeda galaxy. It is part of a larger grouping known as the Virgo supercluster.

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Etymology

Origin of Local Group

First recorded in 1915–20

Example Sentences

A powerful computer then evolved this early universe forward in time, eventually producing a system that matches the present day Local Group.

From Science Daily • Mar. 6, 2026

Despite the gravitational pull of the Local Group, galaxies within the plane are influenced by additional mass spread throughout that same plane.

From Science Daily • Mar. 6, 2026

"I am excited to see that, based purely on the motions of galaxies, we can determine a mass distribution that corresponds to the positions of galaxies within and just outside the Local Group."

From Science Daily • Mar. 6, 2026

The mass concentrated at the center of the Virgo Cluster exerts a gravitational force on the Local Group.

From Textbooks • Oct. 13, 2016

What we actually see, however, is almost exclusively red shifts no matter what distant objects beyond the Local Group we point our telescopes to.

From "Cosmos" by Carl Sagan