OT: So if Jupiter is something of a "failed star", how much bigger would it have to be to be a successful star, and what would be the effect (if any) on other planets' orbits, and would it boil away a lot of Saturn ?

Wikipedia says it would need to be 75x more massive in order to start fusing hydrogen.

https://en.wikipedia.org/wiki/Jupiter#Size_and_mass

I wonder then how this idea of "failed star" got um started.