Answer:

Explanation:
v = Orbital speed = 130 km/s
d = Diameter = 16 ly
r = Radius = 
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

As the centripetal force balances the gravitational energy we have the following relation

Mass of the the massive object at the center of the Milky Way galaxy is 
Answer:
the Princess in "St. George and the Dragon"