Star Trails Compendium

CYRARIAN WEATHER

The climate on Cyraria is one of dramatic extremes, from as cold as -60 degrees Celsius (C)/-76 degrees Fahrenheit (F) to 106 degrees C/222 degrees F. While the lemniscadian orbit is partly to blame, the 87 degrees inclination of the planet's axis is a major factor. Earth is only 23 degrees from the vertical yet this accounts for the seasons as one hemisphere then the other leans toward the Sun. This changes the Sun's declination (height in the sky), making its rays hotter the higher it gets, as well as defining the length of the ecliptic (path across the sky) which determines the number of hours of daylight.

Cyraria, however, is tipped on its side and is thus closer to being horizontal than vertical. Thus there are times when its northern hemisphere is facing either Zeta or Zinni constantly while the southern is in complete darkness and vice versa. Sigma3/Epsilon is at 45 degrees North Latitude so is halfway between the planets north pole and equator. This tempers its seasons slightly versus what it is at extreme locations but still results in dramatic and lethal differences.

The length of the seasons differ dramatically as well. This is due to the nature of elliptical orbits. According to Kepler's 3rd Law of Planetary Motion, a planet will sweep out "equal area in equal time." The illustration at the top of this section is not to scale but you can get the idea that when the planet is between Zeta and Zinni in its Opposition period the area shown is relatively small compared to that at the opposite ends, such as its Ecli-noctial periods. Thus, the planet actually moves faster in its orbit during the smaller sectors than the larger ones. This is fortunate considering that Opposition temperatures are extremely high. Furthermore, when the planet is between the two stars it undergoes tremendous gravitational forces in opposite directions which could tear it apart. At the least it will experience groundquakes and various other disturbances during this relatively short but precarious time which has a duration of over two Earth years.

A lemniscadian orbit is unstable and highly unlikely to occur. The theory behind it is that the third component of the star system, a dG7 orange dwarf star with an orbital period of a thousand years, nudged it into that configuration. It's possible the next pass could pull it back to a simple ellipse around both stars, depending on the planet's location at the next transit.

Temperature extremes between the north and south hemispheres contribute to severe weather such as pressure vortices (PVs), or tornados as they're known on Earth. When cold air and hot air mix the convection forces can form a funnel as the hot air rises and cold air drops. The temperatures would be even more extreme if it weren't for the thick atmosphere which contains a significant amount of dust. During the PV season more dust is stirred up which actually helps opposition temperatures from being even higher.