Unbarred Spiral Galaxies

These disk galaxies have spiral arms as their main identifying feature, although the number of arms, as well as how tightly wound they are, varies from galaxy to galaxy. Spiral arms are very prominent due to the fact that dust and gas at those locations is denser than other places of the galaxy, leading to increased star formation rates. Among these newly-born stars are stars more massive than the Sun, the largest of which shine more brightly and in bluer colours than their less massive counterparts.

For more cool facts about spiral galaxies, click this link!