Classify Planet Type

This function returns a compact four-character code representing the classification of an exoplanet based on its mass, equilibrium temperature, orbital eccentricity, and density.

The classification code is composed of four parts:

1. Mass class:

   • M: Mercury-like planets (< 0.22 Earth masses)

   • E: Earth-like planets (0.22–2.2 Earth masses)

   • S: Super-Earths (2.2–22 Earth masses)

   • N: Neptune-like planets (22–127 Earth masses)

   • J: Jupiter-like giants (127–4450 Earth masses)

   • D: Degenerate-matter/brown dwarf-like objects (>= 4450 Earth masses)

2. Temperature class:

   • F: Frozen (T < 250 K)

   • W: Temperate/water zone (250–450 K)

   • G: Gaseous (450–1000 K)

   • R: Roasters (>= 1000 K)

3. Eccentricity:

   • First decimal digit of orbital eccentricity. For example, 0.26 → 3 → appended as 3.

4. Density-based surface/composition class:

   • g: Gas-dominated (< 0.25 g/cm³)

   • w: Water/ice-rich (0.25–2 g/cm³)

   • t: Terrestrial/rocky (2–6 g/cm³)

   • i: Iron-rich (6–13 g/cm³)

   • s: Super-dense (>= 13 g/cm³)

Usage

classify_planet_type(pl_bmasse, pl_eqt, pl_orbeccen, pl_dens)

Arguments

pl_bmasse

Numeric. Planetary mass in Earth masses. Must be > 0.

pl_eqt

Numeric. Planetary equilibrium temperature in Kelvin. Must be > 0.

pl_orbeccen

Numeric. Orbital eccentricity. Must be > 0.

pl_dens

Numeric. Planetary density in g/cm³. Must be > 0.

Value

A character string containing a 4-character planet classification code.

Examples

classify_planet_type(1.0, 288, 0.0167, 5.5)   # Earth-like: "EW0t"
#> [1] "EW0t"
classify_planet_type(318, 1300, 0.05, 1.3)    # Hot Jupiter: "JR3w"
#> [1] "JR0w"
classify_planet_type(0.1, 180, 0.2, 0.1)      # Cold, light, low-density: "MF2g"
#> [1] "MF2g"