Duke_of_Blandford_II t1_iuctans wrote on October 30, 2022 at 10:40 AM

There isn't "more" gravity. Because the mass of the dead star is so dense the gravity has a stronger localised force.

[deleted] OP t1_iuctoqk wrote on October 30, 2022 at 10:46 AM

So I’m correct in thinking that the gravity does not change because the mass does not change.

But having an increased density, all the mass packed into a smaller area, does what exactly? I understand what has changed but I don’t understand how it affects the object’s pull.

ExtonGuy t1_iucws7k wrote on October 30, 2022 at 11:26 AM

Same “amount” of gravity in less space, close to the BH. if you were the same distance above the star and the BH, you would feel the same force. But with a BH, you can get 100 km (for example) from the center and still be outside the BH. With a star, if you were 100 km from the center you would be deep inside.

Rear-gunner t1_iucuibj wrote on October 30, 2022 at 10:57 AM

You are right that the gravity energy and force is unchanged. Nothing changes in this respect

Duke_of_Blandford_II t1_iucvdmv wrote on October 30, 2022 at 11:08 AM

I'm no expert but as I understand it the effect would be that the gravity would have a stronger pull in a local area, but would have no affect beyond the original footprint of the former star. Planetary orbits wouldn't change unless the black hole sucks in additional mass.