Planet X found

[WaffenVW]

Aperture synthesis only makes a big antennae out of many small ones. It is still a passive system that needs something to radiate energy for the antennae to pick up. Out there 200 times the distance of Neptune the Sun is just a slightly brighter star in the darkness of space.

[Zimme83]

There are several conventional telescopes that are capable of spotting a potential planet nine.

http://www.sciencemag.org/news/2016/01/feature-astronomers-say-neptune-sized-planet-lurks-unseen-solar-system

One telescope can help: Subaru, an 8-meter telescope in Hawaii that is owned by Japan. It has enough light-gathering area to detect such a faint object, coupled with a huge field of view—75 times larger than that of a Keck telescope. That allows astronomers to scan large swaths of the sky each night. Batygin and Brown are using Subaru to look for Planet X—and they are coordinating their efforts with their erstwhile competitors, Sheppard and Trujillo, who have also joined the hunt with Subaru. Brown says it will take about 5 years for the two teams to search most of the area where Planet X could be lurking.

[Chalenge]

Aperture synthesis only makes a big antennae out of many small ones. It is still a passive system that needs something to radiate energy for the antennae to pick up. Out there 200 times the distance of Neptune the Sun is just a slightly brighter star in the darkness of space.

You're arguing the wrong point. The odds of a planet sized object having no magnetic field whatsoever is slim. The odds of any body in space having zero gravity is zero. The way an array like this finds dark bodies/masses in space, is by measuring the effects of those bodies/masses upon radio sources from distant galaxies, or some special cases distant stars within our own galaxy.