#the dimensions for candidate 1 are between 3.3 and 7 earth radii

[powdermelonkeg]

Cybertron's Location

Okay so Alpha Centauri is named as Cybertron's star system in multiple continuities.

Easy, right? Just make up a planet for Cybertron to be. Plausible enough that there's one out there we don't know about.

NOPE. I found a spot for it.

The Alpha Centauri system has three stars in it. These are Rigil Kentaurus (α Centauri A), Toliman (α Centauri B), and Proxima Centauri (α Centauri C). I'm going to be calling them by their non-ABC names for distinction.

Alpha Centauri, as we see it, is Rigil Kentaurus and Toliman's lights being indistinguishable from one another. Those two are a binary star system of sun-like stars, so their orbit intersects and they look something like this:

Meanwhile, Proxima Centauri is a red dwarf, and orbits at a pretty far distance, like so:

It's still part of the same star system because it still orbits around a common point, but in any planet that orbits Proxima, Rigil and Toliman just look like exceptionally bright stars in its sky.

So the question THEN is, which star does Cybertron orbit?

Proxima's the most obvious candidate. It even has a full planetary system:

Proxima Centauri b is in Proxima's habitable zone (the area where water could feasibly exist as liquid), and it's just a little bigger than Earth.

Generally speaking, Cybertron is depicted as larger than Earth, so let's set that aside for this post.

Proxima Centauri d is a tiny planet that's closer to Proxima and no smaller than a third Earth's size.

Proxima Centauri c is either a super-Earth or a gas dwarf, about 7 times Earth's mass, which is disputed both in its nature and whether or not it's really a planet (it's complicated). Regardless, it's outside the habitable zone.

So it could be Proxima c. That's our default option. The biggest problem is the lack of a habitable zone, because, while giant robots don't necessarily need comfortable heat to live, there's the whole "acid rain" and "sea of rust" deal that'd be hard in a planet that far from its sun.

Granted, sometimes Cybertron is seen hurtling through space without a sun or any of those features to speak of, but I'd like to account for it.

So what about the other two?

Toliman was claimed to have a planet orbiting it in 2012 (α Centauri Bb), but by 2016, it was more or less conceded that said planet didn't exist.

Rigil Kentaurus, on the other hand...

Meet Candidate 1 (α Centauri Ab).

It orbits within Rigil's habitable zone, has a period of about a year, and has a mass between Neptune and half of Saturn, with possible habitable moons.

Does it exist? Maybe.

The thing is about Candidate 1 (yes that is its real name) is that it wasn't observed for long enough to confirm its existence. It COULD be a planet. It could also be dust that got captured, or an artifact of the observational instruments.

THIS is my proposal for Cybertron.

TLDR: There's a (possible) planet that orbits the brightest star of the Alpha Centauri star system in its habitable zone and it's bigger than Earth.