i've checked the wiki, i cannot tell if research point limits is a function of rank or planets owned.
which is it?

Rank. AP and MP limits are based on planets.

thnx
do you know where i can find list of breakdown for research point limits vs. rank?

I think it may be 150 per level, that's what mine is right now. You can mouse-over where it says your research production and it will tell you your storage limit, so you can check if that's correct.

This is correct. 150 per level.

thankl you

sorry but what is AP and MP mean?

AP= artifact points
MP= mineral/mining points