Yup, space police. Not sure if they're around in every system but I'd think so.
They say you can play this game as a space pirate, but I just don't see how. Attacking any capital ship gets you sentinels, which spawn in an infinite loop of more and more ships and seems to do that in every system.
Is there some way to mark space stations so that they are at least visible? In my first solar system, the space station was automatically marked and fairly easy to navigate to as a result.
I've discovered and explored all 4 planets in my current solar system and still can't locate a space station.
The icon seems to go away when you're close to it. Pulse engine away a bit and it should show up.