My study area lies on **Tekuo**, an Earth-like planet inhabited by sentient hominids. Tekuo is one of seven planets orbiting a class G2 sun, known as **Aju**. The first four planets in the system are rocky. Tekuo is the third of these. Three gas giants lie in the outer part of the system. Tekuo is the only planet in the system to lie in the habitable zone.

Aju has 1.02 times the mass of our sun, Sol. The luminosity of a body is the cube of its mass, which makes Aju 1.07 times as luminous as Sol.

It is a good job that Aju is brighter than Sol, because Tekuo lies further from Aju than Earth does from Sol. The distance from Aju to Tekuo is 1.03 times the distance from Sol to Earth. This distance is the square root of Aju’s luminosity and hence the distance at which Tekuo receives the same amount of light as Earth.

The time it takes a planet to orbit a sun is the square root of the cube of the distance between them. So Tekuo’s year is equivalent to 1.05 Earth years, that is to say 385.33 days.

Tekuo is around 0.9 times the size of Earth. Earth has a single moon, 0.0123 times its size. Tekuo has two moons. Together, these are 0.01 times the size of their planet.