"Was Planet 9 once an exoplanet, stolen by our sun?" Topic

"Through a computer-simulated study, astronomers at Lund University in Sweden show that it is highly likely that the so-called Planet 9 is an exoplanet. This would make it the first exoplanet to be discovered inside our own solar system. The theory is that our sun, in its youth some 4.5 billion years ago, stole Planet 9 from its original star.

An extrasolar planet, or exoplanet, is by definition a planet located outside our solar system. Now it appears that this definition is no longer viable. According to astronomers in Lund, there is a lot to indicate that Planet 9 was captured by the young sun and has been a part of our solar system completely undetected ever since.

"It is almost ironic that while astronomers often find exoplanets hundreds of light years away in other solar systems, there's probably one hiding in our own backyard," says Alexander Mustill, astronomer at Lund University.

Stars are born in clusters and often pass by one another. It is during these encounters that a star can "steal" one or more planets in orbit around another star. This is probably what happened when our own sun captured Planet 9…"

Amicalement
Armand

Its name is Pluto. And this theory is at least a century old.

Interesting that Pluto and the other Kuiper Belt objects like Haumea, Sedna, Eris, MakeMake, Snow White, etc. seem to be in some kind of resonance orbit with this planet 9. The weird orbits means mathmatically, the planet has been proven to exist and must be in a certain size range.

Even without the mystery #9, Pluto isn't necessarily 9. Eris is near identical in size to Pluto.