Iris System

 

Diagram of the Iris System. Distances are not to scale; sizes are roughly to scale. Note that only notable moons are shown in this diagram; smaller, more minor moons have been omitted.

Diagram of the Virvn System. Distances are not to scale; sizes are roughly to scale. Note that only notable moons are shown in this diagram; smaller, more minor moons have been omitted.

Diagram of the Kelda System. Distances are not to scale; sizes are roughly to scale. Note that only notable moons are shown in this diagram; smaller, more minor moons have been omitted.

Iris System

Age	~6.9 billion years
Location	Orion Arm, Milky Way Galaxy
Nearest star	GJ 3323 (3.6238 ly)
Nearest known planetary system	GJ 3323 (3.6238 ly)
Planetary system
Semi-major axis of outer known planet	Iris: 10.5 AU (Sarius) Virvn: 0.69 AU (Elthiame) Kelda: 2.14 AU (Kalgamania)
Populations
Known stars	3 (Iris, Virvn, Kelda)
Known planets	Iris: 11 (7 terrestrial planets, 4 gas giants) Virvn: 4 (2 terrestrial planets, 2 gas giants) Kelda: 8 (2 terrestrial planets, 6 gas giants)
Known dwarf planets	27 (known)
Star-related properties
Spectral type	Iris: K0.5V Virvn: DA4 Kelda: M4.5V

The Iris System is a triple star system located approximately 16.34 light-years from the Sun and 12.11 light-years from the Ingffhaestian System. The system is known to humans as 40 Eridani and contains three stellar components: the orange main sequence star Iris, the white dwarf Virvn, and the red dwarf Kelda.

The Iris System serves as the home system of two sentient species: the firefly-like Florania species (native to Iris' fifth planet, Heafea) and the gelatinous Lemurian Slimes (native to Iris' sixth planet, Lemuria). Semi-sentient species with intellect akin to non-human primates on Earth also exist on the planets Onett and Graptopetalum. While the Lemurian Slimes remained relatively insular and isolated, the Floranias took to colonizing the entire system. These colonizations remained peaceful until the 19th Century, when the expansionist and Social Darwinist Holy Thritanian Empire seized control of Heafea and proceeded to aggressively conquer the star system's other worlds. Non-Heafean denizens of the Iris System suffered under Thritania's oppressive rule until a rebellion led by exiled Thritanian princess Lemrina vi Thritania encouraged Thritania to withdraw from its colonies. Shortly after, however, the entire system was annexed by the Kingdom of Kerolon.

With a combined total of 23 planets, the Iris System is among the largest discovered star systems in terms of celestial body count as well as the second largest of the 14 lifebearing systems controlled by Uingffh’s nations. It sits behind only Ingffhaestia itself in system size, with Ingffhaestia boasting 38 total planets.

Structure and Composition

The Iris System’s three stellar objects of Iris, Kelda, and Virvn form the dominant gravitational centers of the system, with all other objects in the system orbiting at least one of the three. As the most massive stellar object, Iris itself constitutes the most dominant gravitational center, though Kelda and Virvn also exert a considerable gravitational influence on the system.

As with most stars, Iris, Kelda, and Virvn all have compositions dominated by hydrogen and helium, as do the system’s giant planets. Iris has a lower concentration of metals and other heavier elements than the Sun - a peculiarity given the high amount of planets orbiting it. Virvn, meanwhile, has outer layers notably rich in hydrogen, as referenced by the “A” partnof its spectral type of DA4.

All three stars boast planetary systems with a similar basic layout to the Solar System, with terrestrial planets occupying inner orbits and giant planets occupying higher orbits - an unusual occurrence. Iris’ planetary system bears the most similarities to that of Sol, albeit with more terrestrial planets. Meanwhile, Kelda had a significantly higher proportion of gas giants in its system while Virvn overall has a much smaller planetary system, likely due to its stellar evolution destroying most inner planets that may have once orbited the star during its main sequence phase.

Unlike the Solar System, the three component systems of Iris do not host circumstellar disks akin to the Kuiper Belt, likely due to their gravitational influence on each other removing material from the peripheries of their planetary systems. However, icy dwarf planets still exist within the system, albeit in more variable locations.

Orbits

Like the Earth's Solar System, all objects in the Iris and Kelda systems all orbit in circular paths on the same plane, or eliptic, while smaller minor bodies such as dwarf planets, asteroids, and comets tend to have more erratic, eccentric, and inclined orbits compared to those of the planets. Minor bodies are relatively few in number due to the influence the three stars have on each other; the few that do exist have even more unusual orbits than many of Earth's minor bodies for the same reason described prior. Many of Iris's planets bear host to large systems of moons, with many of them being tidally locked to their parent planets. The Kelda System's planets tend to have less moons due to their systems' compactness, which restricts the number of stable orbits possible moons can have.

Also like the Solar System, most objects in the Iris Star System's three component planetary systems orbit in the same direction as Iris's rotation (which is counterclockwise) while moons do the same, but with their parent planet. Exceptions to both cases exist and are much more common in small, minor objects like comets, though a few large moons have retrograde orbits.

The Virvn System constitutes a noteworthy exception to the greater Iris System's orbital trends; Virvn's four remaining planets exhibit somewhat more erratic and eccentric orbits than most other planetary systems. This is likely due to Virvn's stellar evolution and contraction into a white dwarf disrupting the orbits of its planets due to a sharp decrease in the star's mass as well as destroying numerous inner planets that may have exerted a significant gravitational influence on the system.

Formation and Evolution

The ages of the Iris System's stars are commonly disputed, but Virvn is commonly accepted as the first of the three stars to form. Iris and Kelda then likely formed shortly after in the same vicinity as Virvn. All three stars formed in a typical fashion for stars: starting out as molecular clouds that soon contracted into protoplanetary disks, and then into main sequence stars.

While Iris' protoplanetary disk likely had properties similar to that of the early Solar System, Kelda and Virvn's protoplanetary disks likely disturbed each other at least somewhat due to the two stellar objects' close proximity to one another. This may form the cause behind the Kelda System's unusually high amount of giant planets, similar to how gravitational interactions between Ingffhaestia and Avimotalis during their formative years may have led to Avimotalis' own high amount of giant planets. Virvn's planetary system may have thus formed a similarly large planetary system.

After planetary formation, the three stars entered the main sequence, which Iris and Kelda currently remain in. Meanwhile, Virvn likely became the most massive star of the system during its main sequence phase; astronomers estimate that main sequence Virvn was an F-type star or a spectral type close to it. Regardless, the star left the main sequence an estimated 1-2 billion years ago and evolved into a red giant, a helium-burning star, and finally an asymptotic giant branch star - a process that destroyed any inner planets that may have existed in the Virvn planetary system during Virvn's main sequence phase.

Future

Iris

As Iris ages, its temperature will gradually increase, which in turn will increase the temperatures of the planets and moons orbiting it. During this process, the larger and more oceanic habitable worlds - Pacifico, Heafea, and Lemuria - will, in that approximate order, lose their habitability and transition into Venusian worlds. Onett, however, has a low chance of becoming a Venusian world due to its smaller size and lower water content; instead, it will likely slowly lose its atmosphere to space. If the rate of its air loss matches the rate of Iris' temperature increases, Onett may be able to sustain its habitability and temperature for long periods of time. Otherwise, however, the planet will likely instead transition into a cold desertic Mars-like planet.

After around 7-10 billion years, Iris will leave the main sequence and rapidly expand into a subgiant, and then a red giant, likely destroying all planets orbiting closer to the star than Heafea at least. It will then contract into a helium-fusing star, expand once more into an asymptotic giant branch (AGB) star, and then shed its outer layers out into a planetary nebula. This process will leave a white dwarf remnant similar to Virvn.

Kelda and Virvn

The stellar evolution of red dwarfs like Kelda and white dwarfs like Virvn is still poorly understood, as no red or white dwarfs in the known universe have advanced into later stages of stellar evolution yet. However, astronomers predict that Kelda will slowly increase in temperature over billions of years, rendering Graptopetalum too warm for habitability in the process. This would culminate in Kelda transitioning into a blue dwarf, and then a white dwarf. Both Kelda's white dwarf remnant and Virvn are then expected to cool down into black dwarfs over even larger periods of time.

Major bodies

Iris

Iris is the eponymous star of the Iris System as well as its largest and most massive star, with a mass roughly 78% of the Sun's and a radius roughly 81.2% of the Sun's. As a star of spectral type K0.5V, Iris has a yellow-orange hue and is on the more luminous end of K-type main sequences stars. On average, Iris has a surface temperature of 5072 Kelvin.

Iris is 6.9 billion years old and its expected to remain on the main sequence for another 7-10 billion years.

Basilio

Basilio is the first planet of the Iris System. It is a small, airless terrestrial planet similar in size and mass to Mercury; due to its lack of atmosphere, Basilio's surface features numerous prominent, well-preserved craters. The planet is not very notable aside from some mining and scientific colonies established by Thritania.

Virvn

Elthiame

HEAVY WIP