Alkypso and Dretuclite
Alkypso and Dretuclite is a binary star system consisting of a hot, young and massive O-type star named Alkypso and a small, old, ultra-cool M-type red dwarf named Dretuclite. Containing a total of 13 planets, a total of 15 moons (excluding asteroid moons), and 9 comets.
Both Alkypso and Dretuclite used to be single star systems. Dretuclite formed 2.5 billion years before Alkypso from a completely different cloud of gas. That changed when Dretuclite passed within a single light year from Alkypso, causing it to be captured by Alkypso's gravity. Dretuclite's gravity also perturbs the cloud of icy planetesimals surrounding Alkypso, sending a swarm of thousands of comets bombarding the inner planets, similar in some way to our solar system's Late Heavy Bombardment.
Alkypso
Alkypso is a young, hot, and extremely massive O-type star, at 8.2 solar mass. It already lost a few percent of its mass, and is about to go supernova within 10 million years.
HermineHermine is the first planet of the Alkypso system. It is a super-earth planet roughly 4.5x the mass of Earth. The planet's mountains are covered in purple-ish sand-like particles, it is unknown what causes this purple color. Overall, most of the terrains are flat with little to no surface features. Average temperature is 450°C, and because the planet has no atmosphere, the day side can become hotter than Mercury, while the dark side could go as low as -95°C.
KnurgilKnurgil is the second planet of the system. It is a super-earth planet 8.3x the mass of Earth. The planet is distinctly white, and has a high albedo of 0.45. It has an extremely fast rotation speed of 3.4 km/s, meaning that a day in Knurgil is just 5 hours and 58 minutes. This also means that, despite the planet having no atmosphere, the temperature difference between the day side and the night side is just 125°C, from 350°C to 225°C.
AlureKnurgil's only natural satellite, nearly three times the mass of Luna. Like all moons, it is tidally locked, meaning that one side is always facing the planet while the other side is always facing away. The longer day (at 8.21 days) means that the temperature difference is greater than on Knurgil. The day side can get as hot as 510°C while the night side can get as cold as -102°C
MikypsiaThe largest rocky planet in the system, at 10x the mass of Earth, and the only planet with a visible ring system. The planet is ominously dark, with a low albedo, a thick atmosphere, and a surface temperature of 502°C. The thick atmosphere, over twice as thick as earth's, makes it better at distributing the star's heat than earth, this means that the night side would only be a few degrees colder than the day side. Clouds do exist in the planet's atmosphere, but instead of made out of water vapor, it's made out of aluminium and glass, and when it falls down, it literally rains glass.
WharvisOne of Mikypsia's three moons. It is 2.85x heavier than Luna. It somehow resembled Saturn’s moon Iapetus, with the brown and white landscape. The moon has an unusually large iron core, which gives the moon a high density.
FienusMikypsia’s second moon. It is 2.57x heavier than Luna. The moon is distinctly blue in color, and it is unknown what causes this blue color. One of the weirdest feature this moon has is that just under 16°N it has this long, really thin mountain range that runs almost perpendicular to the latitude line. Some theories suggest that it’s an inactive reverse fault line.
ManescuManescu is the furthest moon of Mikypsia. It is 2.12x heavier than Luna, slightly heavier than Jupiter’s Ganymede. It orbits 1.91° below the actual orbital plane of the other two moons. The moon’s surface is distinctly orange, with blue on the highlands. The terrain is very rugged, with extreme cliffs and steep hills. The southern plateau covers an area a little over half as wide as the contiguous United States, and it has some of the most extreme terrains in the moon, with insane cliffs that are comparable to Mars’ Valles Marineris, which isn’t even a near 90° cliff.
DhirbekkDhirbekk is a gas giant exactly half the mass of Jupiter, and almost exactly 200000 km wide, which is wider than Jupiter, suggesting that it’s a very low density planet. The planet’s atmosphere, which is mainly composed of ammonia, nitrogen, and argon, is divided into five belts: the south pole, the orange belt, the equatorial belt, the blue belt, and the north pole. The south pole surrounds the south pole, and is mostly blue-ish white. The orange belt is, as the name suggests, orange in color, and mainly surrounds the southern mid-latitude. The equatorial belt is a mix of orange color and blue color, with a little bit of white. The blue belt is, well, I don’t need to explain it to you, and mainly surrounds the northern mid-latitude. The north pole surrounds the north pole and is distinctly greenish yellow in color.
RoefnorRoefnor, Dhirbekk’s only major moon, is often called “Mars’ darker cousin”, this is mainly because of it’s dark red color, almost as if it was tanned. Roefnor is situated on the edge of Dhirbekk’s Van Allen belt, which subjects the moon into huge amounts of radiation. Average temperature is 140°C
GnizgervGnizgerv is the most massive planet in the whole system, at 3.23x the mass of Jupiter. Gnizgerv is separated from Dhirbekk by a grand distance of 71 AU, you could comfortably fit the entire solar system within it, and there’s still room for Pluto. What’s really weird about Gnizgerv is that it rotates on the opposite direction, and it’s not a slow rotation either like Venus, this planet rotates once every 7 hours and 39 minutes. The magnetic poles are also inverted, with the south being north and the north being south, and the magnetic field extremely powerful, at 18.5 gauss, nearly twice as powerful as Jupiter’s magnetic field. This also means that the Van Allen belt extends much further than Jupiter. Another odd thing is that this planet hosts two planetary mass moons, and they’re not small either, one of them is 3.5x heavier than Earth, that’s larger than all of the rocky planets in the Dretuclite system. This, along with the fast rotation and the retrograde rotation, baffles scientists and astronomers.
PruhetaniaPruhetania, Gnizgerv’s innermost major moon, has an extremely rugged terrain. While most of the mountains are not that high, the steep hills and extreme elevation differences makes for a world that is barely navigable. Dry riverbeds can be seen across the surface, it’s unclear whether Pruhetania used to have liquid water on its surface.
ScironAn cold world covered in ice, Sciron is similar in many ways to Jupiter’s Europa. While having a surface temperature of -108°C, liquid water could exist under the surface thanks to geothermal activities, which could host multicellular lifeforms under its surface.
DrevdiakDrevdiak came so close to being Earth-like, with liquid water, land, and an atmopshere, but due to the fact that the moon is still in its adolescence (at least, compared to Earth), it wouldn’t be for another one billion year until life resembling that of the Earth to develop, as right now the landmasses are just boring rock and sand and the ocean only has microbes, and Alkypso would’ve already went supernova long before that. The earliest life forms on earth lived 250 million years after Earth had formed, and considering that the whole system (excluding Dretuclite) is just under 32 million years, y- you already know my point.
VardekkVardekk, at just under half the mass of Luna, has an unusually high density, it’s denser than all the other moons, denser than even Alex Jones. One theory suggests that Vardekk might have collided with another moon in the past, ejecting away its outer layers and leaving the mantle and core behind.
StoetzelStoetzel, at 1.81x the mass of Luna, is very similar to Sciron, with a subsurface ocean under its ice that might host multicellular lifeforms. Interestingly, the ice layers acts like a crust, and has tectonic plates, meaning that earthquakes are frequent in this moon.
AshkykAshkyk stands out from the rest of the moons in the system as it is extremely huge, not 10x the mass of Luna, not 50 either, but 288x the mass of Luna, roughly 3.5x the mass of Earth. That, along with Anaetua accounts for 99.91% of the total mass of the entire Gnizgervian moon system. It is yet unknown how Ashkyk grows to become so huge, but with that kind of size comes some very interesting stuff (that’s what she said). Ashkyk is covered in liquid water, and has an earth-like atmosphere, key feature for life to develop. Life actually developed quite early in this moon, much earlier than Earth, several small marine creatures can be found swimming in the 800 km deep ocean. However, due to Gnizgerv’s tidal force, the moon is in a 1:2 rotation-orbit resonance, meaning that a day in here is over 78.5 days long, and continues to slow down. Moreover, the long rotation period causes the temperature difference between the day side and the night side to be much greater, even with an atmosphere. This means that at noon, the ocean temperature could get as high as 42°C, which could generate severe thunderstorms and hurricanes.
ZackZack is a moon, orbiting around Ashkyk, which is also a moon. This submoon is actually pretty heavy, at 0.6x the mass of Luna, larger than Vardekk. It is likely that Zack used to orbit Gnizgerv before being captured by Ashkyk’s gravity.
AnaetuaThis weird gas giant planet which keeps hammering astronomers with questions not only hosts one planetary-mass moon, but two. This one is a lot smaller, at 1.23x the mass of the Earth, and unlike Ashkyk, it has no life. But it does have two moons, Yortuon and Themysca, both of them are asteroids.
Dretuclite
Dretuclite is an old, ultra-cool red dwarf roughly 81.7x the mass of Jupiter, or 0.078x the mass of Sol. It's so dim that it'll be indistinguishable from any other stars in the night sky as seen from the Alkypso system, while Alkypso itself would appear as bright as a full moon as seen from the Dretuclite system, and 10x as bright during closest approach. The star also orbits in a retrograde motion, at least from Alkypso's perspective. The planetary system is made up of 8 planets, with two being habitable. The star is also orbited by asteroids captured from the cloud of icy asteroids surrounding Alkypso
YustrippeYustrippe is the innermost planet of the Dretuclite system, it is 8.34x the mass of Luna, about as heavy as Mars, but a lot denser. Its surface is a lot like the Moon, almost entirely gray. Like nearly all planets orbiting around a red dwarf, it is tidally locked, meaning that one side is always facing the star while the other side is always facing away. The day side can get as hot as 310°C while the night side is always under -210°C.
AzgarrAzgarr is the second planet of the Dretuclite system. It is 25.4x the mass of Luna, and has orange mountains with blue lowlands. This planet has not much to offer, like all the other planets, it is tidally locked, and it has no life.
DhekmulDhekmul is third planet of the system with a 10.8x the mass of Luna. The planet is a lot denser than all the other planet in the system, at 6.2 g/cm
3. The terrain is pretty flat, with the highest point reaching 3200 m up.
ThegrunThegrun is a Venus-sized desert planet with an earth-like atmosphere, several liquid water lakes and a diverse amount of species. The whole planet is essentially a large desert with very few vegetation. Large lakes can be seen, most of them are larger than the Caspian sea. Thousands of different species can be found around the terminator line, the line that divides between day and night, where the temperature is just right. However, because there are very few plants scattered across the planet, most of the species are carnivorous.
XigleionXigleion is a water world planet 52x the mass of Luna. This planet has an extremely diverse marine ecosystem with hundreds of thousands of marine creatures, from near the surface to the very bottom of the thousand-mile deep ocean, from small microorganisms to monstrous aquatic creatures. The far side is all covered in ice, and has all types of creatures walking among the frozen land.
CraunidesA large, cold and icy planet 2.13x the mass of Earth, the most massive of the Dretuclite system. Craunides has an extremely high albedo of 0.82, so even the bulls-eye remains well below 0°C. It has an incredibly thin atmosphere similar to Pluto's atmosphere, and it's mostly made up of ammonia and nitrogen. Like Europa, it likely has a subsurface ocean where multicellular life could develop.
DargDarg is a cold, barren planet with 1.65x the mass of Earth. The average surface temperature is -146°C, the bulls eye being -11°C, and the far side being -243°C. Despite being the farthest planet in the system, it is still tidally locked.