The planets in the Duallan System are as follows:
1. Iota Prime is a very small planet about .4 AU's from Iota Centauri. Its close proximity to the star prevents any atmospheric formation. In addition, its surface is continuously molten on the light side. The planet rotates approximately once every 386 e arth days, and orbits IC about once every 114 earth days. Due to the slow rotation and the lack of an atmosphere, temperatures on Iota Prime vary from about 3 degrees kelvin to well over 3000 degrees.
2. Iota 2 is also a fairly small planet, slightly over half the diameter of earth. Its atmosphere is composed almost entirely of carbon-dioxide, with some carbon-monoxide. There is no free O2 in the atmosphere, nor are there any water molecules. There is a fair amount of ozone in the upper atmosphere, ironically, bringing the temperature down to an average of about 186 degrees celsius.
3. Iota 3 is a comparatively large planet, about 20% larger than earth. It has an atmosphere composed of a mixture of oxygen, hydrogen, helium, nitrogen, and other trace gasses. Its atmosphere is relatively similar to earth, and plant life flourishes ther e. However, its proximity to the sun, only about 1.06 AU's, coupled with the lack of ozone in its upper atmosphere, allow excessively high levels of gamma and ultraviolet radiation. Thus, animal life, at least on the surface, is impossible.
4. Iota 4, common name: Duallus, is a somewhat smaller planet. Because the Iota Centauri star is somewhat larger and hotter than Sol, Iota 4's 1.26 AU distance from the star places it near the center of the habitable zone. It has a diameter about 92% that of earth. Oddly, its rotation is backwards from that of earth, unlike all the other planets in the system except Iota 7, which appears to be in a flat spin.
5. Iota 5 is the closest thing that the Duallan system has to a gas giant. While the planet does not appear to have a central rocky core, its size, a mere 10% larger than Iota 3 and abobut fifty percent larger than Duallus, makes it far too small for a ty pical gas giant in a system the size of Iota Centauri.
6. Iota 6 is a large, rocky planet wih a low, ground-hugging atmosphere of carbon dioxide. Pockets of oxygen-rich atmosphere exist in caves deep wihin the planet, many within close proximity to magma pockets. Areas of liquid water also exist in these area s because of the heat from the magma pockets, thus, there is a slight possibility of plant life in these zones, although this would be rather unlikely.
7. Iota 7 is a medium sized ball of rock. It does not appear to have a molten core, nor does it show any signs of an atmosphere. It does, however, show traces of certain heavy metals that exist only in the upper atmosphere of Iota 5. It is therefore belie ved that Iota 7 was originally a moon of Iota 5. The conditions that caused this moon to break its orbit may have been the same conditions that reduced the number of planets in the system, although any such theories are purely speculation at this time.