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Cosmology

Milky Way

Definition

The barred spiral galaxy containing our solar system, with an estimated 100-400 billion stars spanning about 100,000 light-years in diameter. Its name derives from its appearance as a milky band of light across the night sky from billions of faint distant stars.

Related Terms

Galaxy

A gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. Galaxies range from ...

Star

A massive, luminous sphere of hot gas held together by gravity, generating energy through nuclear fusion. Stars range fr...

Black Hole

A region of spacetime where gravity is so strong that nothing, not even light, can escape once past the event horizon. B...

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