206 lines
7.0 KiB
JavaScript
206 lines
7.0 KiB
JavaScript
'use strict';
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Object.defineProperty(exports, '__esModule', { value: true });
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var base = require('./base.cjs');
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var nutation = require('./nutation.cjs');
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var planetposition = require('./planetposition.cjs');
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/**
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* @copyright 2013 Sonia Keys
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* @copyright 2016 commenthol
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* @license MIT
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* @module jupiter
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*/
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/**
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* Physical computes quantities for physical observations of Jupiter.
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*
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* All angular results in radians.
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*
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* @param {number} jde - Julian ephemeris day
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* @param {Planet} earth
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* @param {Planet} jupiter
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* @return {Array}
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* {number} DS - Planetocentric declination of the Sun.
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* {number} DE - Planetocentric declination of the Earth.
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* {number} ω1 - Longitude of the System I central meridian of the illuminated disk,
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* as seen from Earth.
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* {number} ω2 - Longitude of the System II central meridian of the illuminated disk,
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* as seen from Earth.
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* {number} P - Geocentric position angle of Jupiter's northern rotation pole.
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*/
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function physical (jde, earth, jupiter) { // (jde float64, earth, jupiter *pp.V87Planet) (DS, DE, ω1, ω2, P float64)
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// Step 1.0
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const d = jde - 2433282.5;
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const T1 = d / base["default"].JulianCentury;
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const p = Math.PI / 180;
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const α0 = 268 * p + 0.1061 * p * T1;
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const δ0 = 64.5 * p - 0.0164 * p * T1;
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// Step 2.0
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const W1 = 17.71 * p + 877.90003539 * p * d;
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const W2 = 16.838 * p + 870.27003539 * p * d;
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// Step 3.0
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const pos = earth.position(jde);
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let [l0, b0, R] = [pos.lon, pos.lat, pos.range];
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const fk5 = planetposition["default"].toFK5(l0, b0, jde);
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l0 = fk5.lon;
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b0 = fk5.lat;
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// Steps 4-7.
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const [sl0, cl0] = base["default"].sincos(l0);
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const sb0 = Math.sin(b0);
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let Δ = 4.0; // surely better than 0.0
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let l = 0;
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let b = 0;
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let r = 0;
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let x = 0;
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let y = 0;
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let z = 0;
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const f = function () {
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const τ = base["default"].lightTime(Δ);
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const pos = jupiter.position(jde - τ);
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l = pos.lon;
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b = pos.lat;
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r = pos.range;
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const fk5 = planetposition["default"].toFK5(l, b, jde);
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l = fk5.lon;
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b = fk5.lat;
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const [sb, cb] = base["default"].sincos(b);
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const [sl, cl] = base["default"].sincos(l);
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// (42.2) p. 289
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x = r * cb * cl - R * cl0;
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y = r * cb * sl - R * sl0;
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z = r * sb - R * sb0;
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// (42.3) p. 289
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Δ = Math.sqrt(x * x + y * y + z * z);
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};
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f();
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f();
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// Step 8.0
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const ε0 = nutation["default"].meanObliquity(jde);
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// Step 9.0
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const [sε0, cε0] = base["default"].sincos(ε0);
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const [sl, cl] = base["default"].sincos(l);
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const [sb, cb] = base["default"].sincos(b);
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const αs = Math.atan2(cε0 * sl - sε0 * sb / cb, cl);
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const δs = Math.asin(cε0 * sb + sε0 * cb * sl);
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// Step 10.0
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const [sδs, cδs] = base["default"].sincos(δs);
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const [sδ0, cδ0] = base["default"].sincos(δ0);
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const DS = Math.asin(-sδ0 * sδs - cδ0 * cδs * Math.cos(α0 - αs));
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// Step 11.0
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const u = y * cε0 - z * sε0;
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const v = y * sε0 + z * cε0;
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let α = Math.atan2(u, x);
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let δ = Math.atan(v / Math.hypot(x, u));
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const [sδ, cδ] = base["default"].sincos(δ);
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const [sα0α, cα0α] = base["default"].sincos(α0 - α);
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const ζ = Math.atan2(sδ0 * cδ * cα0α - sδ * cδ0, cδ * sα0α);
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// Step 12.0
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const DE = Math.asin(-sδ0 * sδ - cδ0 * cδ * Math.cos(α0 - α));
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// Step 13.0
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let ω1 = W1 - ζ - 5.07033 * p * Δ;
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let ω2 = W2 - ζ - 5.02626 * p * Δ;
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// Step 14.0
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let C = (2 * r * Δ + R * R - r * r - Δ * Δ) / (4 * r * Δ);
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if (Math.sin(l - l0) < 0) {
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C = -C;
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}
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ω1 = base["default"].pmod(ω1 + C, 2 * Math.PI);
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ω2 = base["default"].pmod(ω2 + C, 2 * Math.PI);
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// Step 15.0
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const [Δψ, Δε] = nutation["default"].nutation(jde);
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const ε = ε0 + Δε;
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// Step 16.0
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const [sε, cε] = base["default"].sincos(ε);
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const [sα, cα] = base["default"].sincos(α);
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α += 0.005693 * p * (cα * cl0 * cε + sα * sl0) / cδ;
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δ += 0.005693 * p * (cl0 * cε * (sε / cε * cδ - sα * sδ) + cα * sδ * sl0);
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// Step 17.0
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const tδ = sδ / cδ;
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const Δα = (cε + sε * sα * tδ) * Δψ - cα * tδ * Δε;
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const Δδ = sε * cα * Δψ + sα * Δε;
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const αʹ = α + Δα;
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const δʹ = δ + Δδ;
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const [sα0, cα0] = base["default"].sincos(α0);
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const tδ0 = sδ0 / cδ0;
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const Δα0 = (cε + sε * sα0 * tδ0) * Δψ - cα0 * tδ0 * Δε;
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const Δδ0 = sε * cα0 * Δψ + sα0 * Δε;
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const α0ʹ = α0 + Δα0;
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const δ0ʹ = δ0 + Δδ0;
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// Step 18.0
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const [sδʹ, cδʹ] = base["default"].sincos(δʹ);
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const [sδ0ʹ, cδ0ʹ] = base["default"].sincos(δ0ʹ);
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const [sα0ʹαʹ, cα0ʹαʹ] = base["default"].sincos(α0ʹ - αʹ);
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// (42.4) p. 290
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let P = Math.atan2(cδ0ʹ * sα0ʹαʹ, sδ0ʹ * cδʹ - cδ0ʹ * sδʹ * cα0ʹαʹ);
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if (P < 0) {
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P += 2 * Math.PI;
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}
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return [DS, DE, ω1, ω2, P]
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}
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/**
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* Physical2 computes quantities for physical observations of Jupiter.
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*
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* Results are less accurate than with Physical().
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* All angular results in radians.
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*
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* @param {number} jde - Julian ephemeris day
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* @return {Array}
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* {number} DS - Planetocentric declination of the Sun.
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* {number} DE - Planetocentric declination of the Earth.
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* {number} ω1 - Longitude of the System I central meridian of the illuminated disk,
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* as seen from Earth.
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* {number} ω2 - Longitude of the System II central meridian of the illuminated disk,
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* as seen from Earth.
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*/
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function physical2 (jde) { // (jde float64) (DS, DE, ω1, ω2 float64)
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const d = jde - base["default"].J2000;
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const p = Math.PI / 180;
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const V = 172.74 * p + 0.00111588 * p * d;
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const M = 357.529 * p + 0.9856003 * p * d;
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const sV = Math.sin(V);
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const N = 20.02 * p + 0.0830853 * p * d + 0.329 * p * sV;
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const J = 66.115 * p + 0.9025179 * p * d - 0.329 * p * sV;
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const [sM, cM] = base["default"].sincos(M);
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const [sN, cN] = base["default"].sincos(N);
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const [s2M, c2M] = base["default"].sincos(2 * M);
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const [s2N, c2N] = base["default"].sincos(2 * N);
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const A = 1.915 * p * sM + 0.02 * p * s2M;
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const B = 5.555 * p * sN + 0.168 * p * s2N;
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const K = J + A - B;
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const R = 1.00014 - 0.01671 * cM - 0.00014 * c2M;
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const r = 5.20872 - 0.25208 * cN - 0.00611 * c2N;
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const [sK, cK] = base["default"].sincos(K);
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const Δ = Math.sqrt(r * r + R * R - 2 * r * R * cK);
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const ψ = Math.asin(R / Δ * sK);
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const dd = d - Δ / 173;
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let ω1 = 210.98 * p + 877.8169088 * p * dd + ψ - B;
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let ω2 = 187.23 * p + 870.1869088 * p * dd + ψ - B;
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let C = Math.sin(ψ / 2);
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C *= C;
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if (sK > 0) {
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C = -C;
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}
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ω1 = base["default"].pmod(ω1 + C, 2 * Math.PI);
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ω2 = base["default"].pmod(ω2 + C, 2 * Math.PI);
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const λ = 34.35 * p + 0.083091 * p * d + 0.329 * p * sV + B;
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const DS = 3.12 * p * Math.sin(λ + 42.8 * p);
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const DE = DS - 2.22 * p * Math.sin(ψ) * Math.cos(λ + 22 * p) -
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1.3 * p * (r - Δ) / Δ * Math.sin(λ - 100.5 * p);
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return [DS, DE, ω1, ω2]
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}
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var jupiter = {
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physical,
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physical2
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};
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exports["default"] = jupiter;
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exports.physical = physical;
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exports.physical2 = physical2;
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