No, that's not what I'm talking about. I mean the circles you see from much further out, like 100 to 50ls or less.
Those rings denote the gravity well around the planet (which affects your supercruise speed as you approach). I'm not sure that they're at precise distances from the planet as I think they're affected by the planet's mass but are intended to act as a warning about the approaching astronomical body much like those stripes on the road leading to a roundabout from UK motorway off-ramp.