interesting illustrations you have here. In he second picture I see they show a "brown dwarf" just outside the orbit of Pluto and the Kuiper Belt. I'm guessing this is the hypothesized "Nemesis" star that some astronomers have wondered about for years. Their thinking is our sun has a very small companion (most stars in the universe are binary systems)star. They think this small brown dwarf star is on an very long elliptical orbit and every 160 million (I think that's the number if I remember right) it's orbit disturbs the Oort cloud and sends literally millions, maybe billions of comets in every direction, including inward towards the inner solar system.
This "Nemesis" star has never been found or even proven to exist. The problem with it is similar to the one of finding comets in the Oort Cloud, it's very far away, it's small and it gives off little if any light.
(A Brown Dwarf is really a failed star. They are larger than Jupiter but much much smaller than then sun. They are really big balls of gas that never had enough material to reach the point where a sustain nuclear reaction would ignite into a full blown star. This is why they are so hard to see.)
As for the idea of the Sun having a companion star, it is possible but unlikely. Most binary star systems see two stars that orbit one another in a rather tight orbit. As far as I know we have never observed a binary star system where the stars' are as spread out as what the Nemesis theory calls for.
This post was edited on 2/25 at 1:18 pm