Figure 13-22 Spiral Galaxies Seen Nearly Edge-on from the Milky Way (a) Because of its large central bulge, this galaxy (called the Sombrero Galaxy) is classified as an Sa. If we could see it face-on, the spiral arms would be tightly wound around a voluminous bulge. (b) Note the smaller central bulge in this Sb galaxy. (c) At visible wavelengths, interstellar dust obscures the relatively insignificant central bulge of this Sc galaxy.