11ac1064_ions___Astronomy___Black_Holes__Question
[Date Answered] April 8, 1998 [Questioner (age, location)] Howard (Australia) [Answer] They actually do have exactly the same gravitational force. Gravity is proportional to mass, so if the mass is exactly the same, they will have the same gravitational attraction. For example, if our Sun were to suddenly become a black hole, the plan ets would experience no change in orbit, because the gravitational pull of the Sun would remain constant. [Question] 
Why is the attraction of a black hole so much greater than the star from which it formed, shouldn't they have the same gravitational attraction?
Quickie Questions - Astronomy - Black Holes