Circumstellar Habitable Zones

Let us consider stars of different types and ask the question whether there exists a habitable zone around them or not. In this context often the term circumstellar habitable zone or ecosphere is used. Obviously, the Earth is located in the center of the HZ of the solar system. Let d denote the mean radius of the habitable zone in AU, L the bolometric luminosity of a star and L the bolometric luminosity of the Sun, then  

Habitable zones around F stars are larger and further away from the star than for the Sun, habitable zones around K and M stars are smaller and nearer to the star (see also e.g. Jones, Sleep, and Underwood, 2006 [173]). 

---

If a habitable zone is restricted to the presence of liquid water, then we must also include the interiors of giant planets and the ice covered Galilean Moons of Jupiter, or the icy satellites of Saturn and maybe even other places. Therefore, the search for life must not be restricted to the study of circumstellar habitable zones. But it seems that life requires much more than just liquid water. 

---