eclipticalToEquatorial: Convert ecliptical to equatorial coordinate

Description Usage Arguments Value Author(s) References See Also


Convert from ecliptical to equatorial coordinates, using equations 8.3 and 8.4 of [1], or, equivalently, equations 12.3 and 12.4 of [2].


eclipticalToEquatorial(lambda, beta, epsilon)



longitude, in degrees, or a data frame containing lambda, beta, and epsilon, in which case the next to arguments are ignored.


geocentric latitude, in degrees


obliquity of the ecliptic, in degrees


A data frame containing columns rightAscension and declination both in degrees.


Dan Kelley, based on formulae in [1] and [2].


1. Meeus, Jean, 1982. Astronomical formuae for Calculators. Willmann-Bell. Richmond VA, USA. 201 pages.

2. Meeus, Jean, 1991. Astronomical algorithms. Willmann-Bell, Richmond VA, USA. 429 pages. The code is based on [1]; see help(moonAngle,"oce") for comments on the differences in formulae found in [2]. Indeed, [2] is only cited here in case readers want to check the ideas of the formulae; DK has found that [2] is available to him via his university library inter-library loan system, whereas he owns a copy of [1].

See Also

Other things related to astronomy: equatorialToLocalHorizontal, julianCenturyAnomaly, julianDay, moonAngle, siderealTime, sunAngle

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