API Reference / EngineData · interface
Interface: EngineData
Properties
| Property | Type | Description |
|---|---|---|
<a id="chebpacks"></a> chebPacks? | Record<string, ChebData> | Heliocentric ecliptic-J2000 Chebyshev packs by body id (ceres, pallas, juno, vesta, pholus, ...). Same pipeline as Chiron. |
<a id="chiron"></a> chiron? | ChebData | - |
<a id="constellations"></a> constellations? | ConstellationPack | Constellation figure lines and labels for SkyView overlays. |
<a id="deepstars"></a> deepStars? | StarPack | Deep naked-eye star pack (HYG to ~mag 6.5), the complete background field for SkyView. Opt-in: node-loaded, not in the embedded web bundle. |
<a id="eartherapacks"></a> earthEraPacks? | ChebData[] | Earth's era slabs, same format and resolution rule as eraPacks. |
<a id="earthpack"></a> earthPack? | ChebData | Heliocentric Earth pack (fit_planet.py earth). Not a chebPacks entry: Earth is never a chart body, it is the observer. Every geocentric direction is body - earth, so Earth's own VSOP error is a floor under every other body, amplified by 1/distance -- which is why packing it lifts the whole chart at once (range-expansion.md Tier C). |
<a id="erapacks"></a> eraPacks? | Record<string, ChebData[]> | Era slabs (deep-time expansion, caelus-deep-time-requirements.md R1): same ChebData format as the default packs, adjoined earlier in time. File naming: {body}_cheb.{era}.json beside {body}_cheb.json, e.g. jupiter_cheb.classical.json. A body resolves at an instant from the slab whose span covers it; the default pack is just the slab with no era in its name. Nothing here changes behaviour where no slab exists. |
<a id="fixedstars"></a> fixedStars? | StarPack | Fixed-star catalog (HYG-derived; ICRS J2000 + proper motions). |
<a id="intpapog"></a> intpApog? | ChebData | Interpolated ("natural") lunar apogee pack: geocentric true-ecliptic- of-date unit vectors, a spline through the Moon's real apogee passages refit as Chebyshev (concept: Swiss Ephemeris General Documentation, Dieter Koch; see python/fit_intp_apog.py). Not a chebPacks entry: those are heliocentric-J2000 and go through the light-time pipeline. |
<a id="keplerpack"></a> keplerPack? | KeplerPack | Hamburg-school (Uranian) constant-element orbits; see fit_uranian.py. |
<a id="mooncheb"></a> moonCheb? | ChebData | - |
<a id="moonerapacks"></a> moonEraPacks? | ChebData[] | The Moon's era slabs, same format; moonPackAt picks the covering slab (the modern tier first, then these). |
<a id="moonmeeus"></a> moonMeeus | MoonSeries | - |
<a id="nutation"></a> nutation | number[][] | - |
<a id="pluto"></a> pluto | number[][] | - |
<a id="vsop"></a> vsop | Record<string, VsopSeries> | - |