meeusjs
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Implementation of the Astronomical Algorithms of Jean Meeus in Javascript
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JavaScript
/**
* @preserve Copyright (c) 2016 Fabio Soldati, www.peakfinder.org
* License MIT: http://www.opensource.org/licenses/MIT
*/
/**
* Defines some constants.
*
* Julian and Besselian years described in chapter 21, Precession.
* T, Julian centuries since J2000 described in chapter 22, Nutation.
*/
A = {
/**
* JMod is the Julian date of the modified Julian date epoch.
* @const {number} JMod
*/
JMod: 2400000.5,
/**
* J2000 is the Julian date corresponding to January 1.5, year 2000.
* @const {number} J2000
*/
J2000: 2451545.0,
/**
* Julian days of 1900.
* @const {number} J1900
*/
J1900: 2415020.0,
/**
* Julian days of B1900 (see p. 133)
* @const {number} B1900
*/
B1900: 2415020.3135,
/**
* Julian days of B1950 (see p. 133)
* @const {number} B1950
*/
B1950: 2433282.4235,
/**
* JulianYear in days.
* @const {number} JulianYear
*/
JulianYear: 365.25, // days
/**
* JulianCentury in days.
* @const {number} JulianCentury
*/
JulianCentury: 36525, // days
/**
* BesselianYear in days.
* @const {number} BesselianYear
*/
BesselianYear: 365.2421988, // days
/**
* AU is one astronomical unit in km.
* This is roughly the distance from Earth to the Sun.
* @const {number} AU
*/
AU: 149597870
};
module.exports = A;