Planet X?
Shouldn't it be called Planet IX now that Pluto's been demoted?
There is still no sign of the elusive Planet X, although astronomers have stumbled across Goblin along the way. A new dwarf world hailed as 2015 TG387 nicknamed Goblin was confirmed by the International Astronomical Union. It was discovered by a group of researchers working at the Carnegie Institution for Science, Northern …
"Only two actual pirates ever really buried their treasure"
Well maybe, but presumably if you were burying treasure, it would be to keep it hidden, so it's not exactly something you'd announce or record in a manner that would be likely to enter the historical record.
In a somewhat related manner, I do know that modern day marine salvagers store some of their finds in specific locations underwater, until they've gathered enough to take it into a port.
Unfortunately for the employer of an acquaintance of mine, the storage site they picked was a shipwreck that they had already cleaned out, and who's location was known. They came back months later to pick up their carefully packaged finds, only to find empty seabed. That was a seven figure loss.
https://en.wikipedia.org/wiki/2015_TG387
With an orbital period of 34,000 years, it goes out to about 2,000 AU at it's furthest distance so the astronomers were lucky to see it. Also, those distant objects tend to have orbital planes that are quite inclined compared to the major planets and so you need to observe a much larger region of the sky to have a chance of seeing them.
There may be (probably are) many more similar objects out there that are just too far away to see or detect at this time, unless we go exploring or make some amazing detection equipment.
Yes, it's an incredible orbit - a perihelion of just under 65AU to an aphelion of just under 2040AU.
That gives it a semi-major axis of just over 1050AU, which I *think* means it doesn't fit my Titius-Bode (re)workings, but my brain doesn't seem to want to work it out properly at the moment. It's been a long week. I want to say the closest point on the sequence at that distance would be 1200AU, but I don't trust my brain right now.
I live on Planet X, as you call it, and I had to relocate here from Mars. You people kept sending your probes crashing into my ham bushes and blanket trees. That got real old. Just so you know, this planet has a steering wheel and thrusters. Screw with me again and I'll take you bastards with me. See if I don't!