In real life, as near as we can tell from the science, the only place you get transported to when you enter a black hole is your own molecules as you’re squished down by incredible gravitational forces. But the phenomena act somewhat differently in No Man’s Sky; popping into a black hole works as a wormhole, popping you out somewhere else. For a long time that was random, but when player Jeff “Husker” D. realized that the black holes were no longer random, he did the logical thing. He started documenting where they led.
The subreddit he founded, Black Hole Suns, is all about finding the various black holes in the game and figuring out where they lead, aiding players in transport all across the game’s maps. It’s work that he’s aware could be completely invalidated by further updates changing how black holes work, either by producing random travel again or just changing destinations, but for now this is a team of players striving to find how to get from place to place via black holes. It’s pretty neat.