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.
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 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.