You can show from basic stellar structure theory that you need a minimum mass of .08 solar masses or so to ignite hydrogen on the p-p cycle. (You can burn heavier isotopes like lithium and deterium at lower masses, but these contribute negligibly to the energy budget of the star because of their low abundances.) .08 solar masses is about 80 Jupiter masses, so this star is over the p-p burning limit. As another author pointed out, the star has a radius comparable to Jupiter. It turns out that due to the physics of degeneracy pressure. Jupiter is about at a maximum in radius for substellar objects.