Help!

Hello!
Ive not played in quite a while, but I distinctly remember encountering… something… when I did. I was traveling toward the galactic centre, and think I was in the region of Coalsack Nebula. Not in it, but near the area. I entered a system and was supercruising around when I kept running into a thing. I remember it was like a black hole, but there were TONS of them, and they were not labelled in the system map, as well as (I think) being different colors. The experience sticks out in my memory as something very distinct, but blurry. For the event, thats literally all I remember. However, as for the emotions it made me feel… keep in mind i was probably around 16 at the time. I had been amazed and awed. This was the only time in my ENTIRETY of play where I was legitimately afraid to go back to that ONE system. I went back another time several months later and it was still freaking scary. I stopped playing not long after Odyssey and this event had happened at least 6 months to a year prior to that. I want help in identifying this phenomena that I remember so strongly. Apologies that I cant remember more… if someone could present a screenshot or tell me keywords to look up so I find it, I would be immensely greatful. Part of what made it so scary was the fact that I had been to Colonia, the Great Annihilator, etc and NEVER encountered anything remotely close to it. Thanks