Black Holes are suspected when a visible star is being noticeably pulled by an invisible partner that is more than 3 times as massive as the Sun. A red giant star is accelerated in a linear direction by gravity at 0.075 m/s2 towards an object that is 9.4 x1010 m away.
a) What is the mass of the invisible star? Answer using scientific notation (eg. 1e+10). kg
b) By what factor is the star more massive than our Sun?