If it were a companion star, then it would have about 2 solar masses and it would be the center of the solar system - which I doubt. In order for a stellar remnant to become a black hole, its mass has to be considerably above the Chandrasekhar Limit. Maybe 2 solar masses is the minimum. That would translate to an original mass of anywhere between 10 and 25 solar masses - a white or blue star, which would have a much shorter lifetime in the main sequence than our Class G yellow dwarf. Less than that, it turns into a neutron star. Ending up as a black hole or neutron star tends to be a very violent end, with a nebula being a calling card of such demise.
Well maybe that’s where the solar system came from