Finding A Transneptunian Planet in IRAS data, Have we found a candidate? Options

[TrappistPlanets]

there is this recent article about finding a possible transneptunian planet candidate
https://arxiv.org/pdf/2111.03831.pdf
The candidate discussed here would be likely to have mass 3-5 MEarth if it was in fact a planet and not something else

what interests me is how we didn't find it in later surveys of the night sky...

[stevesliva]

There is an afterword in that paper that had me checking the Brown & Batygin blog here. There are a few 2021 updates that I hadn't seen.

[TrappistPlanets]

There is an afterword in that paper that had me checking the Brown & Batygin blog here. There are a few 2021 updates that I hadn't seen.

interesting, scale diagram is nice, that size is a bit more realistic for a planet that may have been thrown out way far by jupiter (this is one of the formation theories), and couldn't grab any more material to grow to the size of the 2 known ice giants