Sunday, February 28, 2010


Actually, two types of spiral galaxies are normally recognized: "ordinary" spirals, such as M74, above. In these the spiral arms reach all the way in to the center of the galaxy. However, in the variant known as a "barred" spiral the arms originate at either end of a "bar" through the center of the galaxy. The figure to the right shows how the Milky Way it thought to appear if viewed from outside.