Milky Way

1. Our home galaxy – a spiral galaxy, a disk of stars with a diameter of roughly hundred thousand light-years and a thickness between three- and six thousand light-years, containing about 100 billions of stars. It also contains a supermassive black hole in its centre – more about that in our spotlight topic The black heart of the Milky Way.

2. As our sun is located within the disk of the Milky Way galaxy, there are directions in which we can observe comparatively few of the other stars in our galaxy (namely as we look perpendicularly to the disk, or nearly so) and directions in which we can see a large amount of stars (as we look approximately in parallel with the disk plane). The result is that there is a dim band in the night sky marking the disk plane (the directions where we see a lot of the other stars). This band is also known as the Milky Way.