Geological / environmental event
Xiantar comes into beeing
The former burning ball of materials cooled down and shot through space. It finally got caught by the sun-twins of Perro and Arraw. Perro is a dark sun, sending out infrared light which gets reflected by Xiantars surface and causes a minumum temperature level of -10°C on the surface at any place on the ball that is Xiantar. Arraw is a orange-yellow star, much larger than Perro and dominating the system of these two stars. Xiantar was pulled into an elliptic centering and started to circle around the two stars (to be exact, around the axis connected the two stars).