T (0–55): stellar flux is compared with the star-adjusted Recent Venus, Runaway Greenhouse, Maximum Greenhouse and Early Mars boundaries. The conservative zone receives 50–55 points; the optimistic extensions receive 30–50.
Sources and transparency
Where every datum came from — and how far it lets us conclude.
This page documents every source family, the live Archive query, the habitable-zone cut, literature policy, update clocks and limitations.
Editorial policySource beside the claim
Each dossier links its studies; this page explains how they are classified and reconciled.
Source of truth
NASA Archive first. Original paper when it matters.
PSCompPars provides one populated row per confirmed planet. It can combine parameters from different studies, making it excellent for a broad catalog, but it does not replace the complete solution in the PS table or the primary publication.
Three clocks
- PSCompPars catalog
- normal cache: 6 h · stale response may persist during 24 h revalidation
- Static fallback snapshot
- Jul 16, 2026
- Editorial and literature review
- Jul 26, 2026
The Atlas query time is not the review date of each planet. PSCompPars does not provide a per-planet update date; follow individual parameter source links where available.
Primary sourceNASA Exoplanet Archive
Source for confirmed planets and official counts.
Primary sourcePSCompPars — composite tableOne row per planet; physical, orbital, stellar, Webb, and spectral parameters.
Primary sourceTAP — query guideProtocol and syntax used by the live catalog.
Primary sourcePS / PSCompPars definitionsMeaning, unit, and provenance of each column.
Primary sourceCalculated and composite valuesHow the Archive selects or calculates derived parameters.
Primary sourcePOE — habitable-zone calculationSimplified optimistic definition used in the primary selection.
Primary sourceArchive detailed countsConfirmed total, discovery methods, and the Kepler habitable-zone statistic.
Primary sourceHabitable Worlds Catalog — PHLExternal comparison of potentially habitable candidates; it does not replace the Archive.
Primary selection
Star-adjusted optimistic and conservative zones
The catalog evaluates incident flux against the four Kopparapu boundaries: Recent Venus, Runaway Greenhouse, Maximum Greenhouse and Early Mars. When stellar effective temperature is available, each boundary is adjusted to the host star.
Seff = Seff,⊙ + aT★ + bT★2 + cT★3 + dT★4
T★ = Teff − 5780 K
The polynomial is calibrated for main-sequence stars from 2,600 K to 7,200 K. Outside that range—or when temperature is missing—the Atlas uses the solar coefficients and lowers evidence confidence.AHI · 0–100
How the Atlas Habitability Index is calculated
The index deliberately answers a narrow question: how compatible are the currently reported bulk parameters with an Earth-like surface-liquid-water scenario? It does not infer an atmosphere, ocean, biosphere or civilization.
S (0–35): radius is the primary proxy, mass is the fallback, and very low bulk density reduces the score. The transition near 1.6 Earth radii is statistical, not a hard statement about any individual world.
O (0–10): low eccentricity receives the highest score because irradiation varies less. Unknown eccentricity receives 5 neutral points and reduces evidence confidence instead of being treated as a measured circular orbit.
Evidence confidence is independent of AHI. It weights flux, stellar temperature, radius, mass, eccentricity, distance, discovery reference, transit geometry, archived spectra and approved Webb observations.
Why is 361 not the catalog total?
“Candidates and Confirmed in Habitable Zone” is a Kepler field statistic including candidates and confirmed objects under the 180–310 K or 0.25–2.2 S⊕ filter. It is not an all-sky count of confirmed planets in habitable zones.