The shapes of Galaxies
A galaxy consists of stars, dust, and gas held together by gravity. Small galaxies have fewer than a billion stars. Astronomers have photographed millions of galaxies through telescopes. They believe there are about 100 billion galaxies in the universe. Each galaxy may hold billions of stars.
Galaxies come in many different shapes and sizes. However, there are four main shapes that we can recognize in the sky.
A spiral galaxy looks like a giant whirlpool of stars with a flattened ball in the middle. Out of this ball come two or more spiral-shaped arms of stars. Our galaxy, the Milky Way, is a spiral galaxy.
A barred spiral galaxy has a sausage shape in the middle. From the ends of the sausage come two spiral arms of stars.
Elliptical galaxies are curved. Some are almost round. Others look like flattened balls or footballs.
Irregular galaxies do not seem to have any special shape. Some look like messy spirals. The Magellanic Clouds, the closest galaxies to ours, are irregular galaxies.
Many galaxies are grouped together in space. Such groups are called clusters of galaxies. Some galaxies stand alone between the clusters.
Picture Credit : Google
