
A few depictions of the habitable zone, or just right temperature regions, in which carbon-based, e.g. retinal, or CHNOPS-based intelligent animate matter, e.g. humans, can exist.

In science, habitable zone is the circumstellar radius or region around stars, at a distance according to which heat radiation yields states of matter from about the freezing point to boiling point of water, in which animate CHNOPS-based matter can exist.

Overview
In 1585, Giordano Bruno, in his On the Infinite, the Universe, and the Worlds, posited that there were many suns with many planets and that those not too cold or not too hot would be "inhabited", although, to note, he did not get into specifics about zones.

In 1974, Henry Swan vicariously defined the habitable zone as a medium powered region, as follows: [1]

“Biosphere: region of energy-supplied liquid water existing terrestrial surface, encompassing steady-state organizations of CHNOPS matrix forms.”

In 2006, Paul Davies, in his The Goldilocks Enigma: Why Is the Universe Just Right for Life?, argues that pictured below;

in which he argues that the earth, with its so-called "bio-friendly" conditions habitable zone (Ѻ) , was fine-tuned by accident, and found in one of many universes.

References
1. Swan, Henry. (1974). Thermoregulation and Bioenergetics: Patterns for Vertebrate Survival (CHNOPS, 9+ pgs; biochemistry, pg. 2). American Elsevier Pub. Co.

External links
● Circumstellar habitable zone – Wikipedia.