Methodology

This page documents exactly how each exoplanet profile on Celestial Editorial is produced, so that researchers can assess reliability and reproducibility.

Primary Data Source

All astrophysical parameters — orbital period, planet mass/radius, host-star properties, distance, discovery metadata — are retrieved from the NASA Exoplanet Archive‘s pscomppars table (Planetary Systems Composite Parameters) via its TAP service. Each row in pscomppars is a per-planet composite of the most reliable published measurement for each field.

Derived Metrics

Planet Type (R⊕ classification)

Each planet is classified by its Earth-radius measurement:

  • Rocky Terrestrial — pl_rade < 1.25
  • Super-Earth — 1.25 ≤ pl_rade < 2.0
  • Sub-Neptune — 2.0 ≤ pl_rade < 4.0
  • Neptune-like — 4.0 ≤ pl_rade < 10.0
  • Gas Giant — pl_rade ≥ 10.0

Earth Similarity Index

We compute ESI using the standard four-parameter form: planet radius, density, equilibrium temperature, and an escape-velocity proxy derived from mass/radius, each weighted and multiplicatively combined. Earth scores 1.0; completely dissimilar worlds approach 0.

Habitable-Zone Position

Our habitable-zone flag is based on stellar insolation flux (pl_insol). We use the conservative-optimistic window of 0.35 ≤ S⊕ ≤ 1.5. A flag of “habitable” means the planet receives stellar flux within this range — it does not guarantee habitability, which also depends on atmosphere, magnetic field, and other factors we do not have data for.

Host Star Classification

We use the first letter of st_spectype when available. For rows where spectral type is missing (approximately 37% of the catalogue), we fall back to a classification derived from effective temperature (st_teff) using Morgan-Keenan temperature boundaries.

Publishing Thresholds

We publish profiles for planets that meet all of:

  • • Non-controversial (pl_controv_flag = 0).
  • • At least 25 of 40 tracked measurements populated.
  • • A unique, unambiguous planet name.

Refresh Cadence

The underlying NASA archive publishes weekly updates. Our snapshot is refreshed approximately monthly — often enough to capture new confirmations, but not so often that stable worlds are edited repeatedly.