# Spiral galaxy

Also called: barred spiral.

A galaxy with a bright central bulge and a flat disk of stars, gas and dust wound into spiral arms.

Spirals are the classic galaxy shape: an old, yellowish central bulge surrounded by a thin, rotating disk where new stars are born along the arms. In about two thirds of them a bar of stars crosses the centre — a barred spiral, like our own [milky way](https://astropilot.space/glossary/milky-way).

Seen face-on (M 51, M 101) their arms can show as mottled brightenings in medium and large telescopes under dark skies; seen side-on they become [edge-on](https://astropilot.space/glossary/edge-on-galaxy) streaks.

**At the eyepiece:** The Whirlpool Galaxy (M 51) is the classic first spiral to try: its arms show in an 8-inch telescope on a dark, moonless night.

**Examples:** [M51](https://astropilot.space/object/M51.md), [M101](https://astropilot.space/object/M101.md), [M33](https://astropilot.space/object/M33.md), [M74](https://astropilot.space/object/M74.md)

**Related:** [Galaxy](https://astropilot.space/glossary/galaxy.md), [Hubble type](https://astropilot.space/glossary/hubble-type.md), [Edge-on galaxy](https://astropilot.space/glossary/edge-on-galaxy.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/spiral-galaxy