The planet orbits a single main sequence orange star. It is accompanied by three small moons. There is a medium sized gas giant, called Allein, orbiting Solitaire (Einsam's sun) at about 2 AU away from it. There are no other planets besides that.
Like most Einsam Class Objects, Solitaire was ejected from the galactic core several billion years ago. The Central black hole of the Milky Way sling-shotted the star out of the center almost 5 Billion years ago.
Solitaire was discovered in 2220 CE, when humanity began to count all Einsam Class Objects. Solitaire was not noted beyond the possibility of having an inhabitable planet. It was not directly in line with Andromeda or any other major galaxy, so it's database entry was never viewed by any human.
Die Pionierin was a generation ship sent from Earth in 6732 CE. It was one of the eleven ships lost in the Generations Catastrophe. The ship was meant to travel to the star Stratos and seed a colony there, however, a glitch in the ship's programming sent it to Einsam instead (the two had similar codes).The ship had primitive warp drive technology, so this made the travel much quicker.
The crew was in stasis all the way until the ship arrived in 16,894 (as the ship was travelling at 10C). Die Pionierin crash landed on Einsam, releasing all of the passengers onto the surface of the planet. The ship had mosr of it's generators destroyed and it's data corrupted, throwing the people of Einsam back into the stone age. Most had no actual survival skills, so in the first year, all but about 200 humans died.
They were thrown into the stone age due to this. Most of their knowledge was lost, as the priority went from creating a stable colony to simple survival. Oral traditions maintained some knowledge, however. Common stories included "boats that could fly" and "humans that would come from heaven to rescue Einsam."
Civilization finally made it back to Einsam in 125234. A research team was looking for the ships lost in the Generations Catastrophe and managed to trace it's trajectory to Einsam. When the team got there, the humans on Einsam have changed significantly. They were taller, developed a sixth finger, grew sharper eyes, gained immunity to many poisons, and thicker skin (better described as a hide).