This is the Talislanta RPG solar system. I'm not going to even try to explain all the things of Talislanta. If you have the game, you can drop it in on your spelljammers as an alien world. It qualifies.
Greater Sun-Size I Red fire body
Lesser Sun-Size G Yellow fire body
Archaeus-Size F Earth body (7 Moons all size C)
Wait a second. Where are the other planets? ^_^
They are gone. During the Great Disaster, magical energy swept across Archaeus. One of the 26 flying cities wass hurled into space (Locus) and has not been seen since A lot of the mystical energy also shot out into space. Part of it caused the old crimsion sun to split and a new yellow sun was born. The other planets broke up and their remains were drawn around Archaeus and they formed the seven moons (Zar-black, Laeolis-blue, Jhang-crimsion, Ardan-purpuls, Phandir-green, Drome-amber, Talisandre-silver).
Locus-This was the capital of the nation of flying cities, but due to decadence, the founders of the city left. Leaving only minor talents behind, save one: Zanillo, the rouge magician. Zanillo loved playing magical pranks on fellow wizards, but this situation he did not find funny at all. Several people died during the flight of Locus, and they all looke to the council, which Zanillo was part of, for guidance. Correction, I should say Zanillo himself, since he was the only survivor of the council. At any moment he had at least several dozen protective spells on him due to him wanting to live to see the humilaition on several arch-mages faces from his jokes. Despite his fun loving ways, he took command of Locus and pooled the remaing wizards into halting the city's motion. They managed to stop it after it got past what would be the shared orbit of the seven moons. Over time, Zanillo managed to get things intoi a semblance of normalcy. Botomancy spells were used to accelarate the growth and size of plants. Enchantment spells got the gravity plane back to where it belonged, undernath the city. During this stressful time, antoher wizard showed up on the city to try and help out. His name was Koraq, and he was one of the founders of Locus. After 3600 years of life, he had found something new. A practical joking wizard working seriously Koraq used his magic to help the Skyships travel through space. The ships set up gardens on the green moon to provide food for Locus. The ships explored the sphere, but didn't know about what lay outside their sphere, nor did they care. Dimensional travel is much easier. On Archaeus there are several permanent portals to various higher, lower, and elematal planes (A dimensional nexus). During this time Zanillo was taught how to increase his life span out thousands of years.
Things would have remained that way, but recently a Neogi Deathspider opened a portal into Archauesspace. The Mindspider attacked one of the Skyships traveling to Locus. The Neogi and Umber Hulks were killed and the slaves were brought to Locus to be questioned. From them, the natives of Locus learned about the Crystal Spheres and the Phlogiston.
Koraq had quickly analyzed the two helms (Lifejammer and Major) that the Neogi had used, as well as the passage device. Using the knowledge he gained, he upped the abilites of the levetationals that were used on the Skyships and made new passage devices.
The Archaens made their way into the flow and started trading with other civilizatons. The thing that gets all the other races is that the Archaeun ships use a levetational that requires no one sitting on it. A Dwarf could use it.
For security reasons Zanillo & Koraq kept the tonnage of the ships the same as humans.
People now flock to Locus as a new trading area. The one place that might be able to break the monopoly of the Arcane. Some have tried to land on Archaues proper, but the Locus fleet repels them. It is believed that the Arcane have made several attempts to destroy Locus, but nothing has yet been proven. But then again, there are theese nice glowing crystaline statues of Arcane near the docks. All the statues have looks of pure horror on them.
Koraq (Mage)-He is incredibly smart. Firmly believes that he has lived twice and he's only going through the motions this time. He has created the Archaeun sphere of Sorcery which allows him to analyze/dupilicate ANY magic. On an average day, he creates 20 new spells. He is always accompanied by a self-aware automoton.
Zanillio (mage/rouge)-gone are the fun days of his youth. He now spendshis time keeping the safety of Locus secured. He has turned the day to day running of the city over to a new council. He has more important things to worry about, like the Arcane. Although he is planning a major joke.
Zanillo's joke-Looking at the Tinker gnomes of Krynn, they have no magic beyond priestly. On other worlds, they can learn Illusionist magic. On Toril, in the lands of fate, there is a certain Shai'ar wizard type-the Technomancer (who has simmilar beliefs to the gnomes). Why can't the gnomes learn Technomancy? Needles to sy, that when he prepares it, he's going to be certain that he has covered his tracks (his fame is known only on Archaeus).