NOTE: This is version 2.0 of the New American Arm – it has been updated from its original version. See here for the full explanation for the change, otherwise read on for the updated Arm!
Next, here’s a look at the New American Arm in the realistic star map. Here’s what it looks like from “above” Sol:
And here’s an easier to understand “subway map” of the Arm:
The New American Arm is not too different from the original one. One of the biggest differences is that it now only shares the Chinese Arm up to Broward (which is now AX Microscopii). Also, Davout (Gliese 682) is now exclusively on the Chinese Arm.
Some stars have been replaced by different ones, because of errors or different astrography:
– Serurier is still Ross 154, but Broward is now AX Microscopii (both stars are shared with the New Chinese Arm).
– Gliese 661 (Red Speck’s original star) is also off-track, so Red Speck is now 2MASS J1835+325 – a young M8.5 Brown Dwarf, somewhat more appropriate for the name of the system!
– Ross 863 (Gliese 655) was also in the wrong spot on the original map – it’s actually located beyond Kingsland on the Extended Australian Arm, not before it. Its spot is now taken by WISE J1738+2732 (another dim Y0 Brown Dwarf).
– Ellis is now 61 Cygni, which is actually quite accessible (it was described as being beyond 7.7ly and ‘inaccessible’ from the network in 2320AD, but on the realistic map it’s very straightforward to get to).
Otherwise, the American Arm remains the same as before – the only other differences are the extensions, which add a lot more systems to it:
– There is a small ‘extension loop’ of systems that can be explored between Clarkestar (Wolf 630) and King (Gliese 673).
– The Australian Arm now extends out for many systems beyond Kingsland, so there’s plenty of room for them to expand into. It also loops around ‘behind’ Kafer Space, providing an opportunity to access a ‘backdoor’ into their systems. The closest system to Kafer Space on the Extended Australian Arm is SDSS J1628+1804, which is 8.56ly from 2MASS J1553+1532, a binary brown dwarf system that is about 7ly from both Gamma and Lambda Serpentis.
– The Beta Aquilae arm branches from Mu Herculis (Hermes). There is a gap of 9.35 ly between Gliese 745 and Mu Herculis (Hermes), which requires a Stutterwarp Tug (there are no brown dwarfs in this region) – another Tug is then required to traverse the 10.9 ly gap between Gliese 745 and Gliese 748 (both Tug routes are shown as dotted lines on the subway map). Gliese 748 is the first accessible system in the Beta Aquilae Cluster (Delta Aquilae is the Aquilan homeworld). Note that nobody is aware of the Aquilans yet in MGT 2300AD, but they are of significant interest in 2320AD.
– The Vega Extension doesn’t contain many particularly interesting stars (Gliese 706 is a K2 V, the rest are M dwarfs), but it’s extra space to expand into.
– Red Speck’s Extension leads to Altair, which would be of scientific interest.
– Gliese 1245’s extension leads to Sigma and Chi Draconis – both potentially habitable systems (G9 V and F7 V respectively). Gliese 1245 is not present on the original maps, and is an ‘extra system’ between Red Speck and Ellis.
– One significant change to canon that I would propose is that the Extension that branches off from 61 Cygni should now be the new Bayern Route (used with the permission of the Americans) – this would make far more sense than the original route, since it actually points directly towards the Pleiades (unlike the canonical route, which goes all the way ‘up’ towards and beyond Aurore on the French Arm before coming back down again). Littlendia would be one of the systems on this route – probably Gliese 75 (a G9 V star similar to their canonical home system).
Interestingly (and unlike the New French Arm), the New American Arm contains several systems that are currently known to have planets – Alpha Centauri has at least one earth-sized planet in a torch orbit around the dimmer B star, there are several superearths orbiting the C component of Gliese 667 (Avalon would be 667Cd or Ce), and Vega has a protoplanetary debris disk and possibly a distant jovian.
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The only problem with Chi Draconis as the host of Earth-like worlds is that its stars orbit each other too closely to maintain habitable worlds in their own stellar habitable zones but too distantly to jointly maintain a A/B habitable zone.
Wow. Spectacular work!
Thanks! Oh, I didn’t realise that Chi Draconis was a binary system… hrm. I’d have to crunch some numbers for a circumbinary habitable zone (if there is one), but maybe a superearth with a dense (high greenhouse effect) atmosphere might be possible in such an orbit?