Bulge

    According to the Hubble Sequence, a "bulge" is one of the characteristics a spiral galaxy. It is at the center of rotation and is mostly composed of small, red and old Population ll stars. These stars are several billion years old, as only ancient stars are crimson and minuscule, and often have gigantic black holes in the center. These "black holes" suck up all light, so direct observation to the bulge is rather hard to observe. Below is a conception of a spiral galaxy's bulge.