Exoplanet Modeling and Analysis Center

Exoplanet Boundary Calculator

Chemical Condensation & Habitable Zone Boundaries

The Exoplanet Boundary Calculator uses a classification scheme that distinguishes exoplanets into different categories based on their size and incident stellar flux. The scheme is based on the known chemical behavior of gases sand condensates at different pressures and temperatures in a planetary atmosphere. Here we initially focus on sphalerite ZnS, H2O, CO2, and CH4. The order in which these species condense in a planetary atmosphere define the boundaries between different classes of planets. Broadly, the planets are divided into rocky planets (0.5–1.0 RE), super-Earths (1.0–1.75 RE), sub-Neptunes (1.75–3.5 RE), sub-Jovians (3.5–6.0 RE), and Jovians (6–14.3 RE) based on their planet sizes, and “hot,” “warm,” and “cold” based on the incident stellar flux.

Instructions: Enter numerical values into the following form fields. Planetary radius should be within the range of roughly 0.5 to 14.3 Earth radii. The default stellar temperature is that of the Sun, and until more models are created for different star types, the Sun's characteristics will determine the outputs. Selecting "No Distance Information" will show a line across the condensation boundaries at the specified radius, while selecting a distance measurement will show a point. Again, the conversion between stellar flux and semi major axis distance is calibrated with the Sun's luminosity.

Species Condensation Flux Boundary
Atmospheric Chemical Boundaries