[2300AD] Realistic Star Map Project: Part III – The New French Arm (v2.0)

NOTE: This is version 2.0 of the New French Arm – it has been significantly updated from its original version. See here for the full explanation for the change, otherwise read on for the updated Arm!

Following on from my overview of what 2300AD’s Arms could look like on a realistic starmap, let’s take a closer look at my reinterpretation of the French Arm (as well as Pentapod and Kafer space) by starting off with a general overview (and some 3D maps!):

View of the French Arm from above.

3D Map of the New French Arm (view from “above”).

This new 3D map shows what the revised “New French Arm” looks like in the realistic starmap, as seen from “above”. The solid blue lines show the explored and colonised parts of the French Arm, the red/pink section is Kafer Space, and the light pink section is Pentapod Space. Dotted lines are “extensions” that haven’t been colonised yet but provide space for future expansion. Sol is located at the bottom left corner of the network, and Pentapod and Kafer space are “above” Sol, closer to the viewer.

While a 3D map is nice to look at to get an idea of the real layout of the stars, they are a little hard to interpret! Fortunately, the nature of the Arms is such that they can be represented using a much simpler “subway map” (shown below) that displays all of the connected systems in and around the French Arm much more clearly. This map was made using the very handy subway map generator at http://beno.org.uk/metromapcreator/ – it has a few quirks (such as not saving the maps properly – some screen capturing and assembly in Photoshop was required!) but it works pretty well once you get used to it.

Subway Map of the French Arm and Alien Space

Subway Map of the French Arm and Alien Space

The subway map shows the Arms and branches much more clearly. I’ve tried to arrange it so that the lines vaguely agree with reality, though in doing so it looks a little un-intuitive – I had to put Sol at the bottom right end of the dark blue line (with the French Arm extending to the left from it) in order to get the Beta Canum Branch on the same side of the map as the Arcturus Branch.

I’ve also had to move some of the named systems around to get the history working with the new map, and also had to incorporate the systems that were at fictional stars or stars that turned out too distant to be usable. I tried to fit the systems to similar stars, but there may be some differences (that probably matter less in the grand scheme of things than their placement on the arms).

So. What do we have now? We’ll actually start from the top of the arm and work down towards Sol.


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The Kafer Sphere: Realistic Kafer Space is somewhat different to what has been presented in canon. It can be divided into two parts – the Psi Serpentis Cluster (the line from Gliese 1191 to HR 606) and the Gamma Serpentis finger (from Psi Serpentis to Alpha Bootis (Arcturus)). The Gamma Serpentis finger contains the only fictional system in the entire Revised Near Sol Map – an L4 V brown dwarf that I have called KF J1545+0546 (its full name is KF J154511.20+054633.4, which are its actual coordinates in RA/Dec as seen from Sol). This BD is required to bridge the 9.1 ly gap between Lambda and Psi Serpentis – without it the Kafers will have no way to reach human space since they do not use Tug technology. This means that the Kafer homeworld must be moved behind the gap so they have a region of space in which to expand before meeting humans at Arcturus.

As a result, the Kafer homeworld is now located at Psi Serpentis, instead of Gamma Serpentis. Psi Serpentis is a binary system with a G5 V primary and a K2 V companion orbiting at a distance of at least 60 AU. Psi Serpentis is more similar to Sol and somewhat dimmer than Gamma Serpentis, which means that the Kafers wouldn’t have needed to adapt to a high UV output from their star – but otherwise they can remain unchanged (their other physical adaptations could easily be a result of a harsh homeworld environment, rather than due to the star itself). Placing the homeworld at Psi Serpentis allows them to expand into the Psi Serpentis Cluster and encounter the Ylii (whose homeworld would now be located at Gliese 583).

Eventually the Kafer would have explored the entire cluster, at which point they needed to find new challenges and new territories. They brought Ylii astronomers to Psi Serpentis in an attempt to locate new routes to the stars (possibly improving their stutterwarp drives at this time) and with their assistance they located the dim brown dwarf KF J1545+0546 at a distance of about 7 lightyears from their home system that allowed them to bridge the gap to Lambda Serpentis. The Kafer then expanded down the Gamma Serpentis finger, where they encountered the humans at Arcturus in the late 2200s. Subsequent encounters then led to war and invasion as described in canon.

It should be noted that Arcturus is not the only system through which Kafers can access Human Space – there are other ‘backdoors’ from Kafer systems that use stars not shown (but within 7.7 ly of eachother). The Kafers can circumvent the French Arm by travelling from Gliese 567 and HIP 75187 to Gliese 519 (Dunkelheim), Gliese 518 (a white dwarf) and Gliese 514 (Kimanjano), but those are the only places from which they can sneak past.

French Arm
Arcturus Branch: The Arcturus Branch contains the Beta Comae and Pentapod Fingers, as well as many of the major worlds of the French Arm. It is also where the vast majority of the action of the Kafer War takes place, since it contains the only direct connection to the Kafer Sphere. Assuming 2320AD is canon, the First Kafer Invasion of 2301 wreaks considerable damage to the worlds of the Beta Comae Finger (Nous Voila at Beta Comae Berenices, Hochbaden at DG Canum Venaticorum, and Dunkelheim at Gliese 519) and the other worlds on the Arcturus Branch until they are stopped at Wolf 498 (the new location of Beowulf, formerly located at Queen Alice’s Star). The Second Kafer Invasion of 2305-2310 would progress even further, bypassing Beowulf (there is a route that goes from Gliese 514 to Gliese 486 to GL Virginis to Wolf 424 that is not shown on the Arms subway map) before the Kafer fleets are broken at Neubayern, now at the red dwarf of Ross 128.

Pentapod Space: The Pentapod Finger was located past Beta Canum on the original 2300AD map, but that would place it too far from Kafer Space for them to be affected by the war – fortunately on the realistic map there is a group of stars available off the Beta Comae Branch that can be used as their territory (shown in pink on the subway map). The Pentapod Homeworld (Lifewater) is now located at HIP 69526, and all the systems beyond Gliese 528 are off-limits to unauthorised human traffic. Gliese 528 itself is the ‘interface world’ between the humans and Pentapods, where both species maintain outposts. A few Kafer scouts probably attempted to cross into Pentapod Space during the war, but were never heard from again. The attack on Star Gazer that ultimately leads to “the Pentapod Revenge” would take place while it was being transported from the Pentapod homeworld deeper into human space (possibly still to Beta Canum, if Star Gazer felt like touring more of the French Arm along the way), most likely at ULAS J1335+1130 or WD 1334+039 (Gliese 518). The two systems beyond Gliese 528 on the other end of the Pentapod Finger from Lifewater have probably been surveyed by the Pentapods, but most of the Pentapods’ interest has been diverted by the opportunities presented by the systems of the French Arm. It should also be noted that the Bayern Route no longer passes through Pentapod Space (since the Pentapods are no longer on the way to the Pleiades) – instead it now leaves human space from Upsilon Andromedae as described in the New American Arm post.

Beta Canum Branch: The “main French Arm” is often considered to extend from Sol to Beta Canum Venaticorum, with the Arcturus Branch splitting from it at Wolf 359. The first important system from Sol is the binary brown dwarf system WISE J1049-5319 (a.k.a. “Luhman 16″). Next is Wolf 359 (Nyotekundu) and Lalande 21185 (Bessieres), and DX Cancri (now Augereau) – Augereau is now also part of the Latin Arm, making it a more strategically important system.

Beyond Augereau (DX Cancri) is the Beta Canum Branch, which contains the major worlds of Kie-Yuma (Xi Ursae Majoris), Sans Souci (Gliese 450), Crater (Gliese 451), Joi (61 Ursae Majoris), and Beta Canum Venaticorum itself (these worlds orbit the same stars as they did in 2300AD canon). These systems would now be largely untouched by the Kafer War since there is no direct access to them from Kafer Space, and the main Kafer fleet doesn’t get past Neubayern (some scouts may get through, but they probably wouldn’t be able to do a lot of damage).

The Extended French Arm: There are now 35 more systems available for expansion from the French Arm (shown in light blue on the subway map). Only the systems closest to the main French Arm would have been surveyed at this time, leaving the rest as a huge frontier to explore. The Extension consists of a loop that goes from the white dwarf at Gliese 518 around to Augereau at Ross 128. Branching off from the loop are two fingers, one of which extends to Alpha Corvi (F1 V), and the other to Alpha Mensae (G7 V).It should be noted that these Extensions are unique to the French Arm – the Chinese and American Arms have their own Extensions.

There is also a new extension from that leads to HR 5634 that (in 2300) is unexplored by both humans and kafer – both sides are too occupied with eachother to devote any forces to investigate the systems down that line at that time, but once the war is over it will provide another expansion route for the humans. This will fill the niche of the “Wolf Cluster” mentioned in some publications – the original ‘Wolf cluster’ was poorly defined but seemed to include Beta and Gamma Virginis (now out of reach) and possibly what I have now defined as Pentapod Space.

Major Changes: As noted, several worlds were moved to different stars to make the history of the invasion work out. One of the biggest changes is that the Kafer homeworld is now at Psi Serpentis (for reasons described earlier). Hochbaden was originally at Gliese 528, but that would put it in Pentapod Space now – it is now located at the red dwarf DG Canum Venaticorum, between Dunkelheim and Beta Comae Berenices. Adlerhorst (formely at fictional Vogelheim) is now located at Xi Bootis, Kimanjano is now at Gliese 514, and Beowulf is at Wolf 498 (which can now also be referred to as Queen Alice’s Star if desired). The Klaxun homeworld remains at Gliese 505, and is accessible from the (new) brown dwarf at ULAS J1335+1130. Augereau (previously at Gliese 412) is now at DX Cancri, and Neubayern (Ross 128) is one of the two gateways to the new frontiers of the Extended French Arm. Placing them like this keeps the systems in roughly the right order going out from Sol, while still keeping the history as intact as possible.

Coming up next – the American Arm!

Previous article: Realistic Near Star Map Project: Part II – Overview
Next article: Realistic Near Star Map Project: Part IV – The New American Arm

6 Responses to “[2300AD] Realistic Star Map Project: Part III – The New French Arm (v2.0)”


  • Excellent work!

  • (aka Damian Lund)
    In your explorations, did you find a system that was slowly drifting out of stutterwarp range? It’d make an interesting story, of a group of colonists who *wanted* to secede from the rest of humanity.

    Of course, if someone wanted to contact them for some reason, they could set up a tug, or take extra drives. A very expensive proposition, needing a very good reason.

    Or maybe a conjunction of distantly orbiting planets that makes the distance *just* doable…?

    • I didn’t look at the proper motions, but there may well be a couple of systems that are drifting beyond 7.7 ly. I think there are three or four that are right on the edge at 7.7 or very close to it (within 0.005 ly). One of these links potentially extends the Sung finger on the Chinese arm out to the 54 Piscium cluster – unfortunately I don’t know whether the gap will be bigger or smaller by 2300 (it’s between 54 Piscium and a 2MASS Brown dwarf, and there are no radial velocities available for the BD). I’m going to assume that it will get to within 7.7 ly by then though – right now it’s only 7.703 lightyears between the two (a mere 190 AU or so over the limit), though to be honest the error bars in the parallaxes mean that it may be within 7.7 ly already anyway.

  • Using your coordinate converter spreadsheet to work out WISE 1049’s coordinates (1.715, -6.319, 0.607) gives a direct link of 7.3LY to Wolf 359

    • Not to put too fine a point on it, but…. “DAMMIT!”. I think I done screwed up on that one – it appears I didn’t convert the XYZ coordinates into Astrosynthesis coordinates. (Note to self, put a honking great note on the Coordinate Converter that says “THIS IS NOT ASTROSYNTHESIS COORDINATES!”). Sigh.

      I think the rest are ok because they were made using the Bulk Converter which does have a clear AS column. But I think you’re right, WISE 1049 is in the wrong place because of that and it DOES grant direct access to Wolf 359. So yay for the French Arm!

      Unfortunately it somewhat buggers the Chinese Arm though – now they have to go the ‘old route’ from Sol to Barnard to Ross 154 to AX Microscopii and then they can rejoin at Epsilon Indi. It’s not too big a pain (and actually maps better to canon) but I’ll have to do some rewriting.

      Thanks for pointing it out though (I think…) ;)

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