The King at the Center
Bright star, would I were steadfast as thou art–
This is a world building piece, talking about my interpretation of the Spelljammer universe. Everyone has their own take on the setting, which is to be expected. I’m talking about mine to provide context for some of the other stuff on this site, and also just for fun. It may even inspire ideas for your setting.
There is no “official” map of the Spelljammer universe. The closest thing there is would be Paul Westermeyer’s map, which is part of his net.book Guide to the Spheres. This map has been expanded upon in many different ways, with perhaps the most popular one being Nerik’s map of the phlogiston. When I started playing with three-dimensional star mapping programs, I used both of these maps, and pieces of others, as raw material. The program I’m using is AstroSynthesis 3.0, from NBOS software. Many gamers may recognize that company as the makers of the Fractal Mapper series. AstroSynthesis has a definite “hard science” slant to it, as I suspect NBOS was thinking in terms of Traveller, Space Opera, or any of the science fiction RPG’s that usually obeys actual physics.
Spelljammer, as we all know, doesn’t follow actual physics. So, I had to customize the living daylights out of the XML database that contains my Spelljammer map. This process is still underway. The fact that the program will permit me to modify and customize so many components of the database structure speaks highly of its use for gamers of all types.
Yes, that was a plug. Go check out the program. If there is interest, I may make my database available for download. Contact me if you are curious.
Anyway, as I worked on my map, and I started tweaking and adding things of my own liking, I found the setting was starting to look like one of the globular clusters. I don’t think that was deliberate, as most Spelljammer maps tend to be two-dimensional “Mercader” projections. But it was starting to bend at the sides, like I was fitting the sprawling map into a semi-closed sphere.
I took this globular cluster idea and ran hard and fast with it. My take on the setting has become a supercluster of stars in a loose sphere, 81 light years in radius. I deliberately chose a power of three for this, for reasons related to ideas I haven’t fleshed out yet. (Spoilers!) Most adventurers will see only a small portion of this map over the course of their lifetime. Unless they are astral elves, of course, but even that has limits.
From what I’ve read, real globular clusters average around a 50 light year radius, so mine is a bit larger. But at the same time, in the real world the member stars average less than one light year apart and are really packed together. The average distance between stars in my cluster is just over five light years (at last check), which is more in line with the general Milky Way galaxy. So while my globular cluster is larger than most real ones, it is considerably less dense. The size also created a sphere that is more than large enough to encompass any map I’ve seen, and then some. I can easily incorporate new ideas, up to and including entire maps, with room to spare. As many of the books point out, space is big.
At the center of this supercluster, at coordinates [0,0,0] is the largest star known to exist: a massive type O supergiant with a diameter close to that of Saturn’s orbit.1 This star is so far away that it’s almost impossible to see, despite it’s size. But some space travelers have been able to discern it from the background light around it. The influence of this massive star has been documented for centuries, even if it’s true nature was unknown until recently. All of the known stars within the Spelljammer setting orbit this blue behemoth is a slow, circular dance. But even so, very little is known about it.
The first real research into this distant star was performed at the Calisto Institute in Terraspace, under the direction of the famous astronomer-sage Themopolus Hub-El. This eccentric but brilliant gnome has been studying the stars for almost a century. It was he and his team that ascertained the approximate size of the star cluster we all live in, and their research continues to this day. The supergiant at the center of the cluster was finally confirmed in 5005 OC, after multiple viewings by the best telescopes available (many using magical enhancements). The name Hub-El and his team ultimately chose for the giant star was Kentros Rex, meaning “The King at the Center.”
No humans are known to have visited this distant system. But it’s entirely possible, in fact likely, that the system has been visited by someone at some point. Ancient charts suggest that the Juna and the Thri-Kreen both knew of the star’s existence. It’s possible that ancient exploration by these groups took place. But currently, such knowledge is lost, or at best missing.
Another major feature of the skies are a matched pair of nebulae called the “Pillars of Eternity.” These two long, narrow clouds originate near Kentros Rex, and observations suggest that they extend to the outer edge of the star cluster, 81 light years away. They travel in opposite directions from the center, along a shared axis. The “northern” pillar passes the edge of known space, and has been observed for centuries. However, no organized exploration of any portion of the nebulae has been recorded. Here too it is very likely that such exploration has taken place at some point, but the information is currently not available. While very little is known about the northern “Pillar of Eternity,” even less is known about the southern one, owing to it’s extreme distance.
There is a theory suggesting that Kentros Rex and the Pillars are somehow related to the life cycle of the known universe. Or at least this portion of it. This theory suggests that Kentros Rex is a vortex for the phlogiston and other facets of the planes, and that it plays a key role in the birth and life of stars. This same theory suggests that the Pillars of Eternity are conduits through which the life force of the universe first flows before dispersing throughout the cosmos. In this analogy, Kentros Rex is akin to a giant heart, the Pillars being two primary arteries, and the phlogiston as the “life blood” of the universe.
Another theory suggests that Kentros Rex isn’t a star at all, but the physical manifestation of a god or demigod. There is circumstantial evidence to support this. Type O supergiant stars generally only last around two millennia2 before they either collapse, or break apart into smaller stars and disperse. Evidence suggests that Kentros Rex has existed for far longer than that, even if it wasn’t confirmed until a few decades ago. In this theory, the role of the Pillars, if they have one, is unknown.
The Spelljammer’s Aid Society, along with the Pragmatic Order of Thought and the Calisto Institute, have been attempting to organize an exploration mission to Kentros Rex, and by extension, portions of the Pillars of Eternity. Progress has been made in the planning, so it is safe to assume it will be attempted within the next ten years. The logistics of such a lengthy voyage, however, are proving prohibitive, so there is no guarantee.
Regardless, until someone actually travels to Kentros Rex, the mysteries of the King at the Center will remain hidden.
Disclaimer
This is obviously a fantasy universe. A type O supergiant isn’t likely to be at the center of a globular cluster. Especially a cluster with slower burning stars like type G or K, which are well established within the Spelljammer setting. (Most of the established fantasy worlds have a “sun” that behaves like a type G or K main sequence star.) A real type O would burn itself out, implode, or otherwise cease before a G or K could reach maturity. It’s also unlikely that a globular cluster would have stars capable of developing or supporting life. The stars are too close together, making the ambient radiation exceptionally high.
But those are real world issues. A fantasy universe doesn’t have to suffer such restrictions. My interpretation of the Spelljammer universe, which I refer to as K-Rex, looks somewhat scientific at the micro level. It may seem more in keeping with science fiction than science fantasy. (Even allowing for the binary gravity constant!) But the further out you zoom, the more fantastic and outrageous it becomes. Mia culpa.
That being said, if you don’t like something I’ve made up for this version of the setting, then don’t use it in yours! As I’ve often said about stuff I make up, keep what you like and dump what you don’t. If the example of my crazy take on this magical universe inspires and fuels your take on the Spelljammer setting, even if you think I’m totally bonkers, then I’ve achieved my goal.
It is not in the stars to hold our destiny, but in ourselves.
1. In the real world, the largest known star, the red supergiant Stephenson 2 DFK 1, approaches this size. Though the discussion is ongoing, as it may actually be more than one star. Webb and Hubble have both viewed it, but owing to it’s extreme distance, questions remain.
2. In this fantasy universe, a type O lasts around 2000 years. In reality they last far longer, but are still short-lived compared to their smaller, slower burning brethren.
The quotes by Keats and Shakespeare were found at AZ Quotes, viewed October 9, 2026.
The image of an O-type star was captured in Celestia. I don’t remember exactly which star this is, though. I want to say 29 Canis Majoris.