Talos never had a planet to begin with. He's not one of the original Aedra. He was man who ascended to BECOME an Aedra. So obviously, there would be no planet for him. Or maybe there is and it's insignificant in the grand scheme of things.

...no?

The Nine have been around since before Skyrim had more than a few sentences to its name. You might as well say that they based them on the Nine ringwraiths.

Anyhow, if people stopped worshiping Talos, he would disappear. And there were Nine Divine when the pantheon was created, but the Ninth Divine Shezarr (Cyrodilic Lorkhan) was forgotten. Talos was his revival, in a sense. Or several senses.

Talos is the enantiomorph of Lorkhan.
Lorkhan, despite arguably being the most important god in the pantheon, doesnt have a planet either.
Talos his planet is Nirn.

Eight became Nine. The nineth that never was.

Probably has a moon some where....

'Nirn, believed to mean Arena in Old Ehlnofex.'
Talos butchered and killed and lied and cheated and played the system until he made himself the Grand Champion.
Want to take the arena apart brick by brick? Going to have to go through that Grand champion in a stand up fight, or get him discredited and thrown out first.