Center of the Milky Way
Observations of stars near the center of our Milky Way Galaxy have shown stars that orbit on Keplerian paths. The star S0-2 has a period of 17 years and a semi-major axis of about 800 astronomical units, where 1 A.U. is the distance from earth to sun, 150,000,000 km. What is the mass of the thing it orbits? (How many solar masses is this? 1 solar mass is 2x1030 kg.)
Star S0-16 passes within 0.01 AU of the unseen object. Calculate the minimum density of this object?