At the Galaxy's Core. Astronomers have observed a small, massive object at the center of the Milky Way galaxy. A ring of material orbits this massive object; the ring has a diameter of about 17.0 light years and an orbital speed of about 130 km/s. (See attached file for full problem description)

A) Determine the mass of the massive object at the center of the Milky Way galaxy. Give your answer in kilograms.
M =

B) Give your answer in solar masses (one solar mass is the mass of the sun).
Take the mass of the Sun to be 1.99 x 10^30 kg
M =

C) Observations of stars, as well as theories of the structure of stars, suggest that it is impossible for a single star to have a mass of more than about 50 solar masses. Can this massive object be a single, ordinary star?

yes
no

D) Many astronomers believe that the massive object at the center of the Milky Way galaxy is a black hole. If so, what must the Schwarzschild radius of this black hole be?
Take the speed of light to be 3.00 x 10^8 m/s.

E) Would a black hole of this size fit inside the earth's orbit around the sun?
yes
no