system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek]Advanced but not warp capable species and the Prime Directive.

So lets say the federation enters a solar system.  This solar system is home to 4 inhabited  M-Class planets/moons.  All of the species are sapient.  
One species is fairly advanced, and has space ships capable of reaching .9c.  
One of the species is around the level of early 80s Earth.  
One is around 2010 Earth.  
And the last is fairly primitive, somewhere around medieval Earth levels.  
The first species has already established contact with the two advanced ones, and uses their ships to run various trade routes.  The three have decided to leave the less advanced one alone for now, although the 2010 one is itching to plunder them for resources.
Unfortunately, seems some calamity is going to wipe out this solar system in a few months.  What can/should/will the Federation ship do in this situation?
gpt
Nobody we've seen has sublight engines capable of 0.9c. The relativistic effects would be a serious issue. Full impulse is 0.25c.

Since they had no FTL technology the Federation would not contact them and do nothing to prevent any catastrophe from occurring.

In fact, even if they did, they wouldn't do anything unless formal relations had been established and they asked.