astronomy-js/dist/astronomy-js.min.js

A lightweight javascript library for astronomical calculations.

/*! MIT License

Copyright (c) 2025 Alexandre Ribeiro

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var AstronomyJS=function(A){"use strict";const l={SOLAR_SYSTEM_OBJECT:"SOLAR_SYSTEM_OBJECT",GREENWICH_OBSERVATORY_COORDINATES:{LATITUDE:51.476852,LONGITUDE:-5e-4,RADIUS:6371046},EPHEMERIS_TYPE:{RISE:{NAME:"RISE",ALTITUDE:"-0.833",IS_GOING_UP:!0},SET:{NAME:"SET",ALTITUDE:"-0.833",IS_GOING_UP:!1},TRANSIT:{NAME:"TRANSIT",ALTITUDE:null,IS_GOING_UP:null},CIVIL_TWILIGHT_START:{NAME:"CIVIL_TWILIGHT_START",ALTITUDE:"-6",IS_GOING_UP:!0},CIVIL_TWILIGHT_END:{NAME:"CIVIL_TWILIGHT_END",ALTITUDE:"-6",IS_GOING_UP:!1},NAUTICAL_TWILIGHT_START:{NAME:"NAUTICAL_TWILIGHT_START",ALTITUDE:"-12",IS_GOING_UP:!0},NAUTICAL_TWILIGHT_END:{NAME:"NAUTICAL_TWILIGHT_END",ALTITUDE:"-12",IS_GOING_UP:!1},ASTRONOMICAL_TWILIGHT_START:{NAME:"ASTRONOMICAL_TWILIGHT_START",ALTITUDE:"-18",IS_GOING_UP:!0},ASTRONOMICAL_TWILIGHT_END:{NAME:"ASTRONOMICAL_TWILIGHT_END",ALTITUDE:"-18",IS_GOING_UP:!1}},MS_PER_DAY:864e5,JULIAN_DAY_OFFSET:24405875e-1,JULIAN_DAY_2000:2451545,EPS:Math.pow(10,-9),NUMBERS_OF_ATTEMPT_TO_GET_POSITIONAL_EPHEMERIS:5,DAYS_PER_JULIAN_CENTURY:36525};class r{static modDegrees(t){for(;t<0;)t=t+360;return t%360}static mod180Degrees(t){const e=this.modDegrees(t);return e>180?e-360:e}static modRadians(t){for(;t<0;)t=t+2*Math.PI;return t%(2*Math.PI)}static modPiRadians(t){const e=this.modRadians(t);return t>Math.PI?e-2*Math.PI:e}static radiansToDegrees(t){return t*180/Math.PI}static degreesToRadians(t){return t*Math.PI/180}static padZero(t){return t=t.toString(),t.length>=2?t:"0"+t}}class d{static julianDate(t){return t/l.MS_PER_DAY+l.JULIAN_DAY_OFFSET}static julianDateToDate(t){return new Date((t-l.JULIAN_DAY_OFFSET)*l.MS_PER_DAY)}static julianDaysSinceEpoch2000(t){return t-l.JULIAN_DAY_2000}static julianCenturiesSinceEpoch2000(t){return this.julianDaysSinceEpoch2000(t)/l.DAYS_PER_JULIAN_CENTURY}static meanSiderealTime(t){const e=this.julianDaysSinceEpoch2000(t),s=this.julianCenturiesSinceEpoch2000(t),a=280.46061837+360.98564736629*e+387933e-9*s*s-s*s*s/3871e4;return r.modDegrees(a)}}class E{constructor(t,e,s){this.x=t,this.y=e,this.z=s}minus(t){return new E(this.x-t.x,this.y-t.y,this.z-t.z)}}class T{constructor(t,e,s){this.latitude=t,this.longitude=e,this.radius=s}toDegrees(){let t=this.latitude,e=this.longitude;return new T(`${t<0?"-":""}${r.padZero(0|(t<0?t=-t:t))}° ${r.padZero(0|t%1*60)}' ${r.padZero(0|t*60%1*60)}''`,`${e<0?"-":""}${r.padZero(0|(e<0?e=-e:e))}° ${r.padZero(0|e%1*60)}' ${r.padZero(0|e*60%1*60)}''`,this.radius)}toHours(){let t=this.latitude,e=this.longitude;return new T(`${t<0?"-":""}${r.padZero(0|(t<0?t=-t:t))}° ${r.padZero(0|t%1*60)}' ${r.padZero(0|t*60%1*60)}''`,`${e<0?"-":""}${r.padZero(0|(e<0?e=-e/15:e=e/15))}h ${r.padZero(0|e%1*60)}m ${r.padZero(0|e*60%1*60)}s`,this.radius)}}class O{constructor(t,e){this.sphericalCoordinates=t||new T(l.GREENWICH_OBSERVATORY_COORDINATES.LATITUDE,l.GREENWICH_OBSERVATORY_COORDINATES.LONGITUDE,l.GREENWICH_OBSERVATORY_COORDINATES.RADIUS),this.solarSystemObject=e}getRectangularObjectCentricCoordinatesForSolarSystemObject(t,e){return t.getRectangularHeliocentricCoordinates(e).minus(this.solarSystemObject.getRectangularHeliocentricCoordinates(e))}getRectangularEquatorialCoordinatesForSolarSystemObject(t,e){const s=this.getRectangularObjectCentricCoordinatesForSolarSystemObject(t,e),a=r.degreesToRadians(this.solarSystemObject.axialTilt);return new E(s.x,s.y*Math.cos(a)-s.z*Math.sin(a),s.y*Math.sin(a)+s.z*Math.cos(a))}getDistanceToSolarSystemObject(t,e){const s=this.getRectangularObjectCentricCoordinatesForSolarSystemObject(t,e);return Math.sqrt(Math.pow(s.x,2)+Math.pow(s.y,2)+Math.pow(s.z,2))}getRADecCoordinatesForSolarSystemObject(t,e){const s=this.getRectangularEquatorialCoordinatesForSolarSystemObject(t,e),a=s.x>0&&s.y<0?360:s.x<0?180:0,o=r.radiansToDegrees(Math.atan(s.y/s.x))+a,n=r.radiansToDegrees(Math.atan(s.z/Math.sqrt(Math.pow(s.x,2)+Math.pow(s.y,2))));return new T(n,o,this.getDistanceToSolarSystemObject(t,e))}getHADecCoordinatesForSolarSystemObject(t,e){const s=this.getRectangularEquatorialCoordinatesForSolarSystemObject(t,e),a=s.x>0&&s.y<0?360:s.x<0?180:0,o=r.radiansToDegrees(Math.atan(s.y/s.x))+a,n=r.modDegrees(this.getLocalSiderealTime(e)-o),c=r.radiansToDegrees(Math.atan(s.z/Math.sqrt(Math.pow(s.x,2)+Math.pow(s.y,2))));return new T(c,n,this.getDistanceToSolarSystemObject(t,e))}getAltAzCoordinatesForEquatorialCoordinates(t,e){const s=r.degreesToRadians(r.modDegrees(t.longitude-this.getLocalSiderealTime(e))),a=r.degreesToRadians(this.sphericalCoordinates.latitude),o=r.degreesToRadians(t.latitude),n=r.radiansToDegrees(Math.asin(Math.sin(a)*Math.sin(o)+Math.cos(a)*Math.cos(o)*Math.cos(s))),c=r.radiansToDegrees(Math.PI-Math.atan2(Math.sin(s),Math.cos(s)*Math.sin(a)-Math.tan(o)*Math.cos(a)));return new T(n,c,null)}getLocalSiderealTime(t){return r.modDegrees(d.meanSiderealTime(t)+this.sphericalCoordinates.longitude)}getObjectTransit(t,e){const s=this.getRADecCoordinatesForSolarSystemObject(t,e).longitude;return this.getLocalSiderealTime(e)-s}getObjectLocalHourAngleForAltitude(t,e,s){const a=r.degreesToRadians(this.sphericalCoordinates.latitude),o=r.degreesToRadians(s),n=r.degreesToRadians(this.getRADecCoordinatesForSolarSystemObject(t,e).latitude),c=(Math.sin(o)-Math.sin(a)*Math.sin(n))/(Math.cos(a)*Math.cos(n));return r.radiansToDegrees(Math.acos(c))}getIterationValueForPositionalEphemerisForObject(t,e,s){if(s===l.EPHEMERIS_TYPE.TRANSIT)return e-this.getObjectTransit(t,e)/15/24;{const a=this.getObjectTransit(t,e),o=this.getObjectLocalHourAngleForAltitude(t,e,s.ALTITUDE),n=r.mod180Degrees(s.IS_GOING_UP?a+o:a-o);return e-n/15/24}}iteratePositionalEphemerisForObject(t,e,s){let a=this.getIterationValueForPositionalEphemerisForObject(t,e,s),o=+a;for(let n=0;n<1e3&&(a=this.getIterationValueForPositionalEphemerisForObject(t,a,s),!(Math.abs(a-o)<10^-5));n++)o=a;return d.julianDateToDate(a)}getCorrectDateForPositionalEphemeris(t,e,s,a){const o=this.iteratePositionalEphemerisForObject(t,e,s);if(a>0&&o.getDate()!==d.julianDateToDate(e).getDate()){const n=d.julianDate(o),c=n>e?-1:1;return this.getCorrectDateForPositionalEphemeris(t,n+c,s,a-1)}else return a===0?null:o}getDateForPositionalEphemeris(t,e,s){return this.getCorrectDateForPositionalEphemeris(t,e,s,l.NUMBERS_OF_ATTEMPT_TO_GET_POSITIONAL_EPHEMERIS)}}class D{constructor(t,e){this.objectType=t,this.name=e}}class u extends D{constructor(t,e,s,a){super(l.SOLAR_SYSTEM_OBJECT,t),this.orbitalParameters=e,this.meanRadius=s,this.axialTilt=a}getRectangularHeliocentricCoordinates(t){const e=d.julianCenturiesSinceEpoch2000(t),s=r.degreesToRadians(this.orbitalParameters.getInclination(e)),a=r.degreesToRadians(this.orbitalParameters.getTrueAnomaly(e)),o=r.degreesToRadians(this.orbitalParameters.getPerihelion(e)),n=r.degreesToRadians(this.orbitalParameters.getAscendingNode(e)),c=this.orbitalParameters.getOrbitRadius(e),g=a+o-n,I=c*(Math.cos(n)*Math.cos(g)-Math.sin(n)*Math.sin(g)*Math.cos(s)),m=c*(Math.sin(n)*Math.cos(g)+Math.cos(n)*Math.sin(g)*Math.cos(s)),M=c*(Math.sin(g)*Math.sin(s));return new E(I,m,M)}}class h{constructor(t,e,s,a,o,n,c,g,I,m,M,H){this.a0=t,this.e0=e,this.i0=s,this.o0=a,this.w0=o,this.l0=n,this.ac=c,this.ec=g,this.ic=I,this.oc=m,this.wc=M,this.lc=H}getSemiMajorAxis(t){return this.a0+this.ac*t}getEccentricity(t){return this.e0+this.ec*t}getInclination(t){return r.modDegrees(this.i0+this.ic/3600*t)}getAscendingNode(t){return r.modDegrees(this.o0+this.oc/3600*t)}getPerihelion(t){return r.modDegrees(this.w0+this.wc/3600*t)}getMeanLongitude(t){return r.modDegrees(this.l0+this.lc/3600*t)}getMeanAnomaly(t){return r.modDegrees(this.getMeanLongitude(t)-this.getPerihelion(t))}getEccentricAnomaly(t){const e=r.degreesToRadians(this.getMeanAnomaly(t)),s=this.getEccentricity(t);let a=e+s*Math.sin(e)*(1+s*Math.cos(e)),o=0,n=0,c=0;for(;c++<1e4&&(o=a-(a-s*Math.sin(a)-e)/(1-s*Math.cos(a)),n=o-a,a=o,!(Math.abs(n)<=l.EPS)););return r.radiansToDegrees(o)}getTrueAnomaly(t){const e=this.getEccentricity(t),s=r.degreesToRadians(this.getEccentricAnomaly(t)),a=2*Math.atan(Math.sqrt((1+e)/(1-e))*Math.tan(.5*s));return r.radiansToDegrees(a)}getOrbitRadius(t){const e=this.getSemiMajorAxis(t),s=this.getEccentricity(t),a=this.getTrueAnomaly(t);return e*(1-Math.pow(s,2))/(1+s*Math.cos(r.degreesToRadians(a)))}}class R extends u{constructor(){const t=new h(.38709893,.20563069,7.00487,48.33167,77.45645,252.25084,66e-8,2527e-8,-23.51,-446.3,573.57,53810162829e-2);super("Mercury",t,2439700,2.04)}}class _ extends u{constructor(){const t=new h(.72333199,.00677323,3.39471,76.68069,131.53298,181.97973,92e-8,-4938e-8,-2.86,-996.89,-108.8,21066413606e-2);super("Venus",t,6051800,2.64)}}class y extends u{constructor(){const t=new h(1.00000011,.01671022,5e-5,-11.26064,102.94719,100.46435,-5e-8,-3804e-8,-46.94,-18228.25,1198.28,12959774063e-2);super("Earth",t,6371e3,23.439281)}}class b extends u{constructor(){const t=new h(1.52366231,.09341233,1.85061,49.57854,336.04084,355.45332,-7221e-8,11902e-8,-25.47,-1020.19,1560.78,6890510378e-2);super("Mars",t,3389500,25.19)}}class C extends u{constructor(){const t=new h(5.20336301,.04839266,1.3053,100.55615,14.75385,34.40438,60737e-8,-1288e-7,-4.15,1217.17,839.93,1092507835e-2);super("Jupiter",t,69911e3,3.13)}}class N extends u{constructor(){const t=new h(9.53707032,.0541506,2.48446,113.71504,92.43194,49.94432,-.0030153,-36762e-8,6.11,-1591.05,-1948.89,440105295e-2);super("Saturn",t,58232e3,26.73)}}class P extends u{constructor(){const t=new h(19.19126393,.04716771,.76986,74.22988,170.96424,313.23218,.00152025,-1915e-7,-2.09,-1681.4,1312.56,154254779e-2);super("Uranus",t,25362e3,97.77)}}class j extends u{constructor(){const t=new h(30.06896348,.00858587,1.76917,131.72169,44.97135,304.88003,-.00125196,251e-7,-3.64,-151.25,-844.43,786449.21);super("Neptune",t,24622e3,28.32)}}const L=[new R,new _,new y,new b,new C,new N,new P,new j];class w extends u{constructor(){const t=new h(39.48168677,.24880766,17.14175,110.30347,113.76329,238.92881,-207e-10,6465e-8,501e-8,-37.033,7.765,145.2078);super("Pluto",t,1188300,122.53)}}const p=[new w];class U extends u{constructor(){super("Sun",null,695508e3)}getRectangularHeliocentricCoordinates(t){return new E(0,0,0)}}const F=[new U].concat(L).concat(p);class S{constructor(){this.skyObjects=[...F],this.astronomicalCalculator=new O,this.julianDate=null,this.date=null}getJulianDate(){return this.julianDate}setJulianDate(t){this.julianDate=t}getDate(){return this.date}setDate(t){this.date=t,this.setJulianDate(d.julianDate(t))}getSkyObjectByName(t){return this.skyObjects.find(e=>e.name===t)||null}getEphemerisTypeByName(t){return Object.values(l.EPHEMERIS_TYPE).find(e=>e.NAME===t)||null}setLocation(t,e,s,a){const o=this.getSkyObjectByName(t);if(!o)throw new Error(`Solar system object "${t}" not found`);this.astronomicalCalculator=new O(new T(e,s,o.meanRadius+a),o)}getLatitudeLongitudeCoordinates(){return{latitude:this.astronomicalCalculator.sphericalCoordinates.latitude,longitude:this.astronomicalCalculator.sphericalCoordinates.longitude}}getRADecCoordinatesForObject(t){const e=this.getSkyObjectByName(t);if(!e||this.julianDate===null)throw new Error("Invalid object name or Julian date not set");return this.astronomicalCalculator.getRADecCoordinatesForSolarSystemObject(e,this.julianDate)}getHADecCoordinatesForObject(t){const e=this.getSkyObjectByName(t);if(!e||this.julianDate===null)throw new Error("Invalid object name or Julian date not set");return this.astronomicalCalculator.getHADecCoordinatesForSolarSystemObject(e,this.julianDate)}getAltAzCoordinatesForObject(t,e){const s=this.getSkyObjectByName(t);if(!s)throw new Error(`Object "${t}" not found`);const a=e?d.julianDate(e):this.julianDate;if(a===null)throw new Error("Reference date not set");const o=this.astronomicalCalculator.getRADecCoordinatesForSolarSystemObject(s,a);return this.astronomicalCalculator.getAltAzCoordinatesForEquatorialCoordinates(o,a)}static initialize(t,e){let s=new S;return s.setLocation("Earth",t,e,0),s.setDate(new Date),s}getEphemerisDateForObject(t,e,s){const a=this.getSkyObjectByName(t),o=this.getEphemerisTypeByName(s);if(!a||!o)throw new Error("Invalid object name or ephemeris type");return this.astronomicalCalculator.getDateForPositionalEphemeris(a,d.julianDate(e),o)}}function G(i,t){return S.initialize(i,t)}return A.AstronomyJS=S,A.initialize=G,Object.defineProperty(A,Symbol.toStringTag,{value:"Module"}),A}({});