AS102 Study Guide - Midterm Guide: Orbital Period
Document Summary
The heart of the bulge, the nucleus of the galaxy, is in the direction of the constellation sagittarius. What we have seen so far tells us that at the heart of the core is a dense mass of stars and dust within a region about 3 ly across. The only possible explanation for the motions of these stars is that the centre must be a massive black hole, something we will discuss in greater detail at the end of this lesson. When this possibility was first proposed (not that many years ago) most astronomers discounted the idea. However, evidence is mounting in this direction and today many astronomers believe this to be the case. In fact, it is now believed that most galaxies have such a black hole at or very near their core. Recall from an earlier discussion that we can use. Thus, we can determine the total mass within the.
