# Calculate the habitable zone of a star based on NASA Exoplanet Archive

I am completely new to this! I am trying to find if an exoplanet in the Exoplanet Archive is the habitable zone of its host star. My intention is to create a new boolean column in a Pandas Dataframe to see if the particular exoplanet resides in the habitable zone of its host star. I do not mind limiting myself to single main-sequence stars.

• I am trying to follow this guide but I am already stuck. Jul 22, 2021 at 17:50

There are online programs to calculate habitable zones.

Here is a link to one:

https://depts.washington.edu/naivpl/content/hz-calculator[1]

But I have to warn you that such calculators suffer from problems.

It is rather difficult to calculate the circumstellar habitable zone for a star, especially since the albedo, atmosphere, and other qualities, of planet will affect its temperature as well as its distance from the star.

Here is a link to a table showing various estimates of the inner or outer edges, or both, of the Sun's circumstellar habitable zone.

https://en.wikipedia.org/wiki/Circumstellar_habitable_zone#Solar_System_estimates[2]

And you could read the various scientific papers that make those estimates and are linked to in the article, and maybe decide which limits to the circumstellar habitable zone seem most probable to you.

And then you could take the luminosity of a star relative to that of the Sun, and multiply the inner and outer edge's by that ratio - or by the square root of that ratio, I think - and find the inner and outer edges of the circumstellar habitable zone of that star.

You will note that some estimates make the circumstellar habitable zone very broad and others very narrow.

If someone is a science fiction writer and wants to put their fictional habitable planet at a distance from the star that will be certain to be considered to be within that star's circumstellar habitable zone in the future when more is known on the subject, he can put the planet at the distance from the star where the planet would receive exactly as much radiation from its star as Earth gets from the Sun.

That might be especially important for a science fiction writer who wants his fictional planet to be habitable for human beings in particular and not just for liquid water based life in general.

https://astronomy.stackexchange.com/questions/40746/how-would-the-characteristics-of-a-habitable-planet-change-with-stars-of-differe/40758#40758[3]

with a table showing the orbital distances at which a planet would receive exactly as much radiation from its star as Earth gets from the Sun, adjusted for the luminosities of various spectral classes of stars.

Note that the circimstellar habitable zone is for worlds with life and liquid water on the surface. It is not for worlds were water is liquid due to internal heat from within the world. There are a few icy moons in the outer solar system, beyond the usual outer limits of the Sun's circumstellar habitable zone, which are believed to possibly or certainly have liquid water oceans beneath their miles deep icy crusts, and those internal oceans are considered to be possible habitats for hypothetical life.

Some possiiblities are discussed at:

https://en.wikipedia.org/wiki/Extraterrestrial_life[4]

I also note that alies lifeforms with hypothetical totally different biochemestries might flourish on planets which outside the circimstellar habitable zones of their stars, being too hot or too cold for liquid water using lifeforms.

Here is a link to an article discussing hypothetical alien biochestries:

https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry[5]