This question asks about the smallest sling shot maneuver performed. What was the smallest intentional, acknowledged slingshot maneuver?
I'm asking how small of an object be to perform a sling shot maneuver around it?
Update I didn't think of Magnestars and micro-blackholes when I wrote this question but the replies are great.
Within our solar system I would guess that an object lacking an atmosphere a spacecraft could get closer to the surface of it during the sling shot.