galaxy

As a galaxy, the Milky Way is actually a giant, as its mass is probably between 750 billion and one trillion solar masses, and its diameter is about 100,000 light years. Radio astronomial investigations of the distribution of hydrogen clouds have revealed that the Milky Way is a spiral galaxy of Hubble type Sb or Sc. Therefore, our galaxy has both a pronounced disk component exhibiting a spiral structure, and a prominent nuclear reagion which is part of a notable bulge/halo component. Decade-long observations have brought up more and more evidence that the Milky Way may also have a bar structure (so that it would be type SB), so that it may look like M61 or M83, and is perhaps best classified as SABbc. Recent investigations have brought up support for the assumption that the Milky Way may even have a pronounced central bar like barred spiral galaxies M58, M91, M95, or M109, and thus be of Hubble type SBb or SBc.