(a) Why is the sun considered to be located in the central disk of our galaxy? (b) What is thought to occupy the center of the disk?

Answer 1

(a) Milky Way photographs show a dark band running down the middle, with approximately equal numbers of stars on each side. That is the way it looks when the observer is near the central plane of the disc.

(b) A black hole has been inferred to be at the center of the Milky Way galaxy, based upon the the mass at the center as determined from velocity measurements of stars orbiting the center.