#gymnome

[whirligig-girl]

GYMNOME

Inner Zwo-Nmu System, Coorbital Planet of gas giant Omen Setting of the game Train Misconductor, and homeworld of slimegirl astronaut Eaurp Guz.

Circumference = 31,960,029m = 130 0000 0000₆љ Radius = 0.7984 R🜨 = 5,086,600m = 12 3322 1344₆љ Gravity = 0.8124 g🜨 = 7.9669 m/s^2 = 105.21514₆ љ/nt^2 Mass = 0.5179 M🜨 = 3.09×10^24 kg = 1.53₆×6^31₆ Zlib Density = 1.0175 ρ🜨 = 5612 kg/m^3 = 534.01₆ Zlib/љ^3 Atmospheric Pressure = 0.7101 Atm🜨

Explanation of the Gymnomi units

Gymnome, Earth, Mars, and two of Omen's moons, Rival and Oldsky, all to scale. (The Moon in front of the Earth is not to scale due to perspective)

Hot and cold semi-omicycle climate maps. Because these were not made with a thinner atmosphere in mind, the difference between the climates during the hot versus cold years may be underexaggerated in these maps.

Satellite color/albedo map (cold climate)

Topographic map.

These maps were created by @MsAsterisk, with the exception of the Satellite color map, which I made.

There is also a Kerbal Space Program planet mod of this system.

Painting of the Zwo-Nmu system

Orbit comparison

Close up of Gymnome's orbital trajectory in an Omen-Zwonmu Rotating Reference Frame. Note that at all times Gymnome is directly orbiting the central star, Zwo-Nmu.

Gymnome encounters Omen roughly every 18 of its own years, 15 Earth years, at which time Omen's gravity pulls it into, say, a lower orbit. Gymnome then speeds up in the lower orbit, and 15 years later it catches up to Omen again, which pulls it into a higher orbit. Now it slows down. Omen catches up in another 15 years and the cycle repeats.

This is known to humans as a Horseshoe orbit. Omen apparitions--when Omen gets bright in the sky--are a sign that it's time to pack up your things and move, for the climate is about to change.

It was the Omen apparition of 2328 that led to the oil reserves freezing over and coal-burning Advanced Steam Locomotives being developed.

[pikablob]

An Archive of Our Own, a project of the Organization for Transformative Works

When the fuel crisis hit, many old Gymnomi steam locomotives found themselves pressed back into service. This is the story of one of them, and the engineer who brought her home.

A very late birthday gift I wrote for @whirligig-girl, based on her world of Gymnome/Mellanus - art also by her :))

[whirligig-girl]

The satellite planets of the gas giant Omen, as well as its largest coorbital: Gymnome, Eaurp Guz's homeworld and the setting of Train Puzzle dot exe.

Oldsky, Lake, and Rival are all also known to have life, with Oldsky having a biosphere that is as fully developed as Gymnome.

The orbits of the moons of Omen. The periods are +25.3 hours, +50.7 hours, -174 hours, +236 hours, and +628 hours. Notably, the largest moon, Oldsky, is an obviously captured satellite in a retrograde orbit, but it is thought that Rival and Wanderer are captured satellites as well, with the only surviving original moons of Omen being the three dead-comet-like inner regular moons, which have 7-10 hour periods, as well as Spark and Lake, though the latter have likely been altered at some point in their history by collisions with protoplanets from the inner Zwo-nmu Star System.

The horseshoe orbit of Gymnome wrt Omen.

Scale comparison.

[whirligig-girl]

Family portrait of the Zwo-nmu planetary system (the system to which Gymnome--Eaurp Guz's homeworld and the setting of train puzzle dot exe (title pending)--belongs).

Labelled version and more below the cut.

The Zwo-nmu system, home to Guz's homeworld Gymnome, is like many planetary systems dominated by gas giants. In fact, the only object that would count as a planet in the IAU's books, which resembles the terrestrial planets in our solar system, is tiny mercury-like "Rabbit" in the gap between Cool Ember and Omen.

Omen swept into the inner system, disrupting the late stages of planetary formation, but capturing Oldsky and Rival as moons and Gymnome as a trojan (which later destabilized into a horseshoe orbit). Glerbuh, Omen's near twin by mass, sucked up most of the remaining gas disk, but there was still plenty of volatile mass to generate the four ice giant planets Glarpi, Shpler, Eauah, Flibul, and most likely the recently discovered Schmitt.

Despite no other gas giants posessing moons as massive as Omen's, each of the large satellites of the other gas giants are still worth considering. Not much is yet known of the moons of the ice giants, but it is known that Glerbuh's diffuse ring is generated by the eruptions from about a dozen small rounded moons, which as they trade eccentricities with one another go in and out of periods of dramatic cryovolcanic activity.

The original system layout drawing produced in early 2023.

Scale comparison between our Sun and Zwo-Nmu, and their planets.

Up close on Omen's moons and Gymnome:

Luna's Blog

The satellite planets of the gas giant Omen, as well as its largest coorbital: Gymnome, Eaurp Guz's homeworld and the setting of Train Puzzl

Close up of Glerbuh:

Luna's Blog

Glerbuh -- widest and 2nd most massive of the giant planets in the Zwo-Nmu system, and the outermost of its two J-class planets. A little le

Fanart of Omen by Tolbachik:

Tolbachik Art

A gift piece of Omen for @whirligig-girl! I had a lot of fun working on this piece, I'm very quickly discovering that gas giants are probabl

[whirligig-girl]

Maps of Gymnome

Home of slimegirl spacefarer Eaurp Guz, and the setting of Train Misconductor.

These maps were all created, based only on a brief sketch by myself, by @msasterisk

heightmap, with two color variations.

Provisional biome maps (Köppen classification scheme), cold semi-omicycle vs hot semi-omicycle.

Provisional population density and migration route map

Satellite color map (created by myself for Goobal Slime World, uses cold semi-omicycle biomes, shows only year-round permanent-ish ice.)

An Omicycle is the time between two apparitions of the gas giant planet Omen, the gas giant planet that Gymnome is a coorbital in a horseshoe orbit around. That's about 30 earth years long. Each apparition, the climate changes from a cold to a hot or vice versa for about 15 Earth years, before the orbits catch up again.

rendition of the situation in KSP with the Principia N-body mod

A semi omicycle is the time between an apparition of Omen, and is not a consistent amount of time (a cold semiomicycle is about a year longer than a hot semiomicycle)