Milky Way Galaxy

Introduction & Top Questions
Major components of the Galaxy
- Star clusters and stellar associations
  - Globular clusters
  - Open clusters
  - Stellar associations
  - Moving groups
- Emission nebulae
- Planetary nebulae
- Supernova remnants
- Dust clouds
- The general interstellar medium
- Companion galaxies
Star populations and movement
- Stars and stellar populations
  - Principal population types
  - The stellar luminosity function
- Density distribution
  - The stellar density near the Sun
  - Density distribution of various types of stars
  - Variations in the stellar density
  - Variation of star density with z distances
- Stellar motions
  - Proper motions
  - Radial velocities
  - Space motions
  - High-velocity stars
- Solar motion
  - Solar motion calculations from radial velocities
  - Solar motion calculations from proper motions
  - Solar motion calculations from space motions
  - Solar motion solutions
The structure and dynamics of the Milky Way Galaxy
- Size
- Structure of the spiral system
  - The nucleus
  - The central bulge
  - The disk
  - The spiral arms
  - The spherical component
  - The massive halo
- Magnetic field
- Rotation
- Mass

References & Edit History Related Topics

Images & Videos

Milky Way Galaxy

Milky Way Galaxy

Milky Way Galaxy

globular cluster M80

open cluster NGC 290

Orion Nebula (M42)

Cat's Eye Nebula

At a Glance

centre of the Milky Way Galaxy

Milky Way Galaxy summary

Related Questions

Milky Way Galaxy — Milky Way Galaxy The Milky Way Galaxy as seen from Earth.

Milky Way Galaxy

astronomy

Also known as: The Galaxy

Written by

Paul W. Hodge

Fact-checked by

Britannica Editors

Last updated

Nov. 13, 2026 •History

Milky Way Galaxy, large spiral system consisting of several hundred billion stars, one of which is the Sun. It takes its name from the Milky Way, the irregular luminous band of stars and gas clouds that stretches across the sky as seen from Earth. Although Earth lies well within the Milky Way Galaxy (sometimes simply called the Galaxy), astronomers do not have as complete an understanding of its nature as they do of some external...

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