It's been a long time since we've had an interesting astrophysics
question here.
The gas giant in question masses ~196000 earth masses or 0.058 solar
masses. The smallest known main sequence star masses around 0.07
solar masses. This means that your "gas giant" is right on the
verge of being either a minimal type M main sequence star or a
maximal brown dwarf, which I can't say. I couldn't find the reference
in Chandrasekhar to the minimal mass to begin fusion and it doesn't
say in bohm-Vitense, Abell, Schwarzschild or Zeilik. Either way,
you have a very borderline case which, if I were able to study, would
mean an excellent thesis at the very least :-) If it is massive enough
to begin fusion, I'm not certain it would be stable. It might be
a new type of variable, a pulsating fuser or something like that.
Note that even without fusion it will put out a lot of heat it stored
virially (is that a word?) during it's condensation. I wouldn't
expect a planet to be habitable near it. Also, since it is so massive,
I wouldn't count on planets whose orbit falls between the proto-star
and the primary to be stable on time scales of millions of years.
My advice? Drop its mass by a factor of 10 when nobody is looking.
Nick Christenson
[email removed]