OMG this must've been my night...
After those Earth likes I saw a blue nebula-like dot on the map - except it was waaaay too small to be a nebula. After close inspection I saw it was indeed a black hole (the one I mentioned above). Since it was so well lit I knew it was discovered already but i had to drop in and see it. And holy crap was it awesome! Probably one of the best looking things in this game so far. I was flying around it for like 20min just drooling at my screen.
Now, after I was done - I filtered the map to show neutron stars. And just my luck - there was a small field 3 jumps away. There was 10-ish of them. So naturally, I start farming one by one without even looking at the star class description since i was expecting them all to be neutron stars. And all of a sudden BAM! I get knocked out of the jump by this beast!
Best part of it - it wasn't discovered!