Strange NPR

[replicant2699 (OP)]

I discovered an NPR in my current game and they seem to be in one of the habitable planets in the system. My sensors read 3.8k TH and 38k EM but other than that they have absolutely nothing, no ships, no ground forces and I believe no installations. My diplo ship is orbiting what I assume to be their homeworld, with her transponder on, but I don't get any notifications about communications. Has anyone experienced something like this before?

[Steve Walmsley]

It could be a pre-industrial NPR.

[Mark Yanning]

Hello guys, talking about NPR, I just found an alien race after 19 system explored.
I went to them system and they shoot down 2 of my exploration ships... I tried again with diplomatic ship (commercial engine and friendly transponder ON), they shot them as well without any warning...
The strange aspect is their tech level, is impressive: missiles at 40.000 km/s and ships speed of 8000 km/s, I barely reach 3000 km/s with my tech.
Game is setting at 25% research, how is possible this big difference in tech? Are they not NPR? I feel i would never catch up with technology and no chance of trying to fight them. Is it normal this huge tech difference? Any suggestion? Thanks in advance 

[Andrew]

It would not be abnormal for a normal npr.
Looking at the picture of the npr in question this is typical for a spoiler race Precursors. They turn up in almost all fiction and are widely discussed. But no details here so its your choice to learn about them

[Mark Yanning]

Nice! I'm gonna leave them for the moment. I guess they are protecting some rare artifacts... I'll wait (probably some centuries) until I got a ship with 9.000 km/s and 50.000 speed missile 
Thank you! 

[Garfunkel]

Impressive thread necromancy. I'll move this thread to spoiler forum.