API Reference / solarEclipseWhere · function

Function: solarEclipseWhere()

function solarEclipseWhere(engine, jd): GeoPoint | null;

Sub-shadow geographic point where the eclipse axis meets the Earth at a Julian Day (UT): the centre line of totality/annularity at that instant. Sample it across the eclipse (e.g. between the SolarEclipse begin and end) to draw the ground track.

Parameters

ParameterTypeDescription
engineEngineThe engine used to evaluate positions.
jdnumberInstant to evaluate, Julian Day (UT) -- typically a SolarEclipse.tMax for the point of greatest eclipse.

Returns

GeoPoint | null

The GeoPoint on the IAU 1976 ellipsoid, or null when the axis misses the Earth (only a partial eclipse exists anywhere then).

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