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Milky Wayclick to hear

Spiral galaxy composed of 200 to 300 billion stars, including the Sun; thought to be 10 billion years old.
Milky Way Milky Way (seen from above) nucleus spiral arm Milky Way (side view) halo disk bulge globular cluster

Milky Way (seen from above) click to hear

From above, the Milky Way appears as a spiral that rotates on itself around a nucleus.

nucleus click to hear

Central region of the bulge; the densest and most luminous region.

spiral arm click to hear

Curved grouping of stars influenced by the rotation of the galaxy around its nucleus.

Milky Way (side view) click to hear

From the side, the Milky Way appears as a disk because its spiral arms are seen from the same angle.

halo click to hear

Region surrounding the galaxy, inhabited by isolated stars or groupings called globular clusters; the halo has a radius of about 50,000 light-years.

disk click to hear

The main part of the galaxy, made up of a bulge and attaching arms.

bulge click to hear

The central bulge of the Milky Way’s disk; the densest region of the Milky Way, with a depth of 15,000 light-years.

globular cluster click to hear

Cluster made up of hundreds of thousands of old stars.