TRAPPIST-1 is the second star of the IA-Revived Galaxy, the second-closest stellar body to Kerbol, and the smallest main-sequence star in the mod. It is a 1/10th-scale recreation of the real star TRAPPIST-1, which had a confirmed planetary system on May 2nd, 2016. The star was added into the mod as a way to honor the event. All of the 7 planets, as of the February 2017 data update, are added in the mod.
"The 'science geek fanfiction' star TRAPPIST-1 is an incredibly famous stellar object among multiple species. It is a teensy ultracool dwarf star, not that much bigger than Jool, with a system of SEVEN Kerbin-sized planets. The amount of such small worlds is unprecidented and allows scientists to finally do in-depth studies of rocky exoplanets." -Kerbal Astronomical Society
TRAPPIST-1 in real life is a tiny M8.2V ultracool dwarf star. It is only 0.114 times the radius of our Sun and a mere 8% its mass. That is equivalent to 1.13 times the size of Jupiter and 84.0 Jupiter masses. Its temperature is just 2,550 Kelvin and is at least 500 million years old. TRAPPIST-1 is 39.5 light-years away from our solar system. It boasts a system of 7 confirmed rocky planets. This is the highest amount of terrestrial worlds in one system, and is tied with HR 8832 and HD 10180 as the star with the most confirmed exoplanets.
In Interstellar Adventure Revived, TRAPPIST-1 is the smallest star in the mod with a radius of 8,143.2 kilometers, not that much larger than the planet Jool. As a result it also has a puny mass and gravitational pull. This star has 0.08 times the mass of Kerbol. It is an M8.2V dwarf, very close to being a brown dwarf and glowing a red-maroon color. The light from TRAPPIST-1 is feeble and barely bright enough to light up objects farther out than 8,000,000 kilometers.
TRAPPIST-1 has a nearly circular orbit in the galaxy. It has an eccentricity of 0.05 and an orbital inclination of 0.3 degrees. The orbit of TRAPPIST-1 is the second-closest to the Kerbol system, residing between the binary star Niobe-Amphion and the Cervantes system. Because of its location, TRAPPIST-1 is one of the easier stars to get to and, due to having so many rocky planets, can be used as a refueling system.
TRAPPIST-1 is the dimmest star in the mod, as well as one of the dimmest stars in any Kopernicus planet pack. It has a feeble luminosity just 0.000525 times that of Kerbol and a sunlight intensity of 0.151. All planets in the system, even the closest, are bathed in a twilight-like maroon glow.
In both real life and in IA-Revived, TRAPPIST-1 has a system of 7 planets. This is the most in any system in the mod as of version 1.2.0. All but one planet have working atmospheres, and four have liquid water oceans.
- THEROS (1b): The first planet of the system, and the second least dense. Its low density implies that during its formation, all the iron in Theros mixed with the silicates, resulting in a planet with no iron core. Theros is covered in giant volcanoes and smothered in a thick atmosphere.
- AUXO (1c): Sometimes thought to be the "twin" of Theros, Auxo has a similar temperature, radius, and atmosphere. However, the planet has an opposite composition of Theros - 50% of its volume is an iron core.
- THALLO (1d): The most Kerbin-like planet ever found. Thallo is between the sizes of Kerbin and Duna, with a surprisingly hefty atmosphere and a composition of 25-30% iron. It has a few small seas and is covered in green photosynthetic bacteria.
- EIAR (1e): Another incredibly Kerbin-like planet, this time nearly the same size as the Kerbal's homeworld. Due to its dim star, life on Eiar has developed to used deep purple-blue pigments to absorb as much light as possible. Eiar is somewhat like a habitable Eve, with purple land and purple skies but won't fry you alive.
- IRENE (1f): The third planet in TRAPPIST-1's habitable zone, and the first potentially habitable ocean world found around another star. Irene has a rather low mass for its size, suggesting a composition of 25% water.
- CARPHO (1g): The final potentially habitable exoplanet of TRAPPIST-1 is Carpho. It has an overwhelming green color, similar to that of Minmus. At first glance Carpho seems to be an ocean world, but besides the ice caps, this world has dozens of small islands.
- CHEIMON (1h): A moderate-sized ice planet located far outside the habitable zone. Cheimon hosts no atmosphere, and its surface is water ice covered in dust-like clay. Deep chasms - possibly evidence of an underground ocean - scar its crust.