Planet 9 is an exoplanet stolen by the sun from its original host star

New research suggests the mysterious and controversial "Planet 9" isn't an original member of our solar system. According to a new computer simulation developed by astronomers at Lund University in Sweden, the ninth planet is an exoplanet -- stolen by the sun from its original host star.
Most stars are born in clusters. The orbits of newborn stars often put them in relatively close proximity. The new simulation suggests that as our sun and another star passed by each other, the gravitational pull of our sun pulled in an exoplanet -- a theft that's gone unnoticed until recently.
It's likely that prior to its kidnapping, Planet 9 -- also known as Planet X -- was bullied to the outer edges its original star system by other planets.
Planet 9 may very well have been 'shoved' by other planets, and when it ended up in an orbit that was too wide around its own star, our sun may have taken the opportunity to steal and capture Planet 9 from its original star. When the sun later departed from the stellar cluster in which it was born, Planet 9 was stuck in an orbit around the sun.

http://www.upi.com/Science_News/201...stolen-exoplanet/4901464705120/?spt=sec&or=sn