I did these some time ago, it is based on the recent Battestar Galactica television show, the premise is what does the Cyrannus System look like 150,000 years later. It is done with the Traveller RPG World codes, but since the Starfinder World code system is not available, I had to use something. I also have maps of the system, and they are quite extensive.
The Cyrannus System in case you are unaware is the home system for Battlestar Galactica and for the spinoff Caprica television series, and of course the spinoff movie Battlestar Galactica: Blood and Chrome.
Now as you may be aware, BSG is not much of a science fantasy with a few exceptions and random sprinklings of the supernatural.
Here is the Wikipedia entry
Here is a Map of the Twelve Colonies not done by me.
It could be of some use in a Starfinder campaign, In my Traveller campaign, it was the site of some pirate activity, there are extensive ruins on all of the planets, and they have since been repopulated, it is mostly a frontier area now.
Here are some more maps of the Cyrannus System that I made.
Orbit Chart A Helios-Alpha: Picon, Caprica, Gemenon, Tauron
Orbit Chart I Caprica-Gemenon binary planet in Helios-Alpha
Orbit Chart B Outer Helios-Alpha System
Orbit Chart C: Helios-Alpha/Beta
Orbit Chart J: Helios-Beta: Leonis, Virgon
Orbit Chart E: Helios-Alpha/Beta-Gamma/Delta (Full System)
Orbit Chart K: Gamma-Delta
Orbit Chart L: Helios-Gamma: Scorpia, Libran, Sagittaron
Orbit Chart M: Helios-Delta: Aerilon, Canceron, Aquaria
Helios:Gamma-Delta out to Ragnar orbit
Here again are the stats for the entire system in one chart, in case I missed something with these maps.
Yep, they are nearly equal in size. Caprica is nearly Earthlike, Gemenon is more rugged and mountainous. Their orbit period is about a month. Of course these names are not the ones used today, Caprica has the lifeforms of Pleistocene Earth, wooly mammoths, Neanderthals and the like. There are ruins of 150,000 year old cities on its surface, most of it is invisible from space, but there are signs. Ruins in the desert are the best preserved, it appears some nuclear war was the cause of their destruction.
If you are wanting realistic orbital ellipses, smaller objects orbit bigger ones, and the barycenter of the system would stay between two worlds of equal mass.
The orbits of similar binary stars would look the same as the orbits of similar binary planets:
From the point of view of Gemenon, Caprica appears to be orbiting it.
Picon is a sort of Pulp Venus, label it "Aphrodite" until we get something better, Gemenon becomes "Selene", Caprica become "Gaia", Tauron becomes "Ares", a sort of Mars with higher gravity. Caprica and the other worlds had some Earth life transported to it, some species appeared after the great cataclysm that wrecked civilization on these planets, and those species do not look capable of space travel by themselves. I have another map of the pair.
Here is a Gemenon oriented map.
Here is a Caprica oriented map. I did the same thing for Traveller before and answered this same question., the orbits shown are the stable ones, these go out to one third the distance between these two worlds. Since Gemenon is slightly smaller, it gets designated as a Moon.
I kind of do not want the extreme tides that come with ellipses, so the orbits are more or less circular, Gemenon by the way would appear twice as large in Caprica's sky as does Earth's Moon from Earth, I is twice as far and four times the size, that is why.