The asterisk means it's a unique racial tech, that you can only get from the Yor. I think it's a 5% bonus to research.
In the Yor tech tree it also leads to research academies (collectives), but I think all you get if you buy the tech is that 5% bonus, not the equivalent slot in the tech research line. I haven't experimented much yet with "unique" tech trades, but I think that's how it works.