Heimr orbits around a binary star called "the sun", which orbit around each other at a slightly slower rate than a Heimr year. This causes fluctuations in strength of the sun every two and a half year period. Heimr warms up during this two and a half year period and then cools down again across the next two and a half year period.
Aspects of Heimr's movements around the sun
Heimr's orbital eccentricity is low at the moment. This means that its orbit around the sun is nearly circular. A high eccentricity would correspond with a strong elliptical orbit and a stark difference between seasons. This eccentricity cycle takes around 100.000 years.
The current tilt of Heimr's axis of rotation is zero degrees: it is oriented at a 90° angle (perpendicular) to the orbital plane. This causes the seasons to be uniform across the entire globe. However, the tilt angle varies between 0-5° with a frequency of 38.000 years.
The precession of the axis wobbles over the course of about 24.000 years.