//[astronomy](../../index.md)/[io.github.cosinekitty.astronomy](index.md)

# Package io.github.cosinekitty.astronomy

## Types

| Name | Summary |
|---|---|
| [Aberration](-aberration/index.md)<br>enum [Aberration](-aberration/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[Aberration](-aberration/index.md)&gt; <br>Aberration calculation options. |
| [ApsisInfo](-apsis-info/index.md)<br>class [ApsisInfo](-apsis-info/index.md)(time: [Time](-time/index.md), kind: [ApsisKind](-apsis-kind/index.md), distanceAu: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>An apsis event: pericenter (closest approach) or apocenter (farthest distance). |
| [ApsisKind](-apsis-kind/index.md)<br>enum [ApsisKind](-apsis-kind/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[ApsisKind](-apsis-kind/index.md)&gt; <br>The type of apsis: pericenter (closest approach) or apocenter (farthest distance). |
| [AtmosphereInfo](-atmosphere-info/index.md)<br>class [AtmosphereInfo](-atmosphere-info/index.md)(pressure: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), temperature: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), density: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Information about idealized atmospheric variables at a given elevation. |
| [AxisInfo](-axis-info/index.md)<br>class [AxisInfo](-axis-info/index.md)(ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), spin: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), north: [Vector](-vector/index.md))<br>Information about a body's rotation axis at a given time. |
| [Body](-body/index.md)<br>enum [Body](-body/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[Body](-body/index.md)&gt; <br>The enumeration of celestial bodies supported by Astronomy Engine. |
| [ConstellationInfo](-constellation-info/index.md)<br>class [ConstellationInfo](-constellation-info/index.md)(symbol: [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html), name: [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html), ra1875: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec1875: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Reports the constellation that a given celestial point lies within. |
| [DateTime](-date-time/index.md)<br>class [DateTime](-date-time/index.md)(year: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), month: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), day: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), hour: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), minute: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), second: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>A universal time resolved into UTC calendar date and time fields. |
| [Direction](-direction/index.md)<br>enum [Direction](-direction/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[Direction](-direction/index.md)&gt; <br>Selects whether to search for a rising event or a setting event for a celestial body. |
| [EarthNotAllowedException](-earth-not-allowed-exception/index.md)<br>class [EarthNotAllowedException](-earth-not-allowed-exception/index.md) : [Exception](https://docs.oracle.com/javase/8/docs/api/java/lang/Exception.html)<br>The Earth is not allowed as the body parameter. |
| [EclipseEvent](-eclipse-event/index.md)<br>class [EclipseEvent](-eclipse-event/index.md)(time: [Time](-time/index.md), altitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Holds a time and the observed altitude of the Sun at that time. |
| [EclipseKind](-eclipse-kind/index.md)<br>enum [EclipseKind](-eclipse-kind/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[EclipseKind](-eclipse-kind/index.md)&gt; <br>The different kinds of lunar/solar eclipses. |
| [Ecliptic](-ecliptic/index.md)<br>data class [Ecliptic](-ecliptic/index.md)(vec: [Vector](-vector/index.md), elat: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), elon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Ecliptic angular and Cartesian coordinates. |
| [ElongationInfo](-elongation-info/index.md)<br>class [ElongationInfo](-elongation-info/index.md)(time: [Time](-time/index.md), visibility: [Visibility](-visibility/index.md), elongation: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), eclipticSeparation: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Contains information about the visibility of a celestial body at a given date and time. |
| [EquatorEpoch](-equator-epoch/index.md)<br>enum [EquatorEpoch](-equator-epoch/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[EquatorEpoch](-equator-epoch/index.md)&gt; <br>Selects the date for which the Earth's equator is to be used for representing equatorial coordinates. |
| [Equatorial](-equatorial/index.md)<br>class [Equatorial](-equatorial/index.md)(ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dist: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), vec: [Vector](-vector/index.md))<br>Equatorial angular and cartesian coordinates. |
| [GlobalSolarEclipseInfo](-global-solar-eclipse-info/index.md)<br>class [GlobalSolarEclipseInfo](-global-solar-eclipse-info/index.md)(kind: [EclipseKind](-eclipse-kind/index.md), obscuration: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), peak: [Time](-time/index.md), distance: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), latitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), longitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Reports the time and geographic location of the peak of a solar eclipse. |
| [GravitySimulator](-gravity-simulator/index.md)<br>class [GravitySimulator](-gravity-simulator/index.md)<br>A simulation of zero or more small bodies moving through the Solar System. |
| [HourAngleInfo](-hour-angle-info/index.md)<br>class [HourAngleInfo](-hour-angle-info/index.md)(time: [Time](-time/index.md), hor: [Topocentric](-topocentric/index.md))<br>Information about a celestial body crossing a specific hour angle. |
| [IlluminationInfo](-illumination-info/index.md)<br>class [IlluminationInfo](-illumination-info/index.md)(time: [Time](-time/index.md), mag: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), phaseAngle: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), phaseFraction: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), helioDist: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), ringTilt: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Information about the brightness and illuminated shape of a celestial body. |
| [InternalError](-internal-error/index.md)<br>class [InternalError](-internal-error/index.md)(message: [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)) : [Exception](https://docs.oracle.com/javase/8/docs/api/java/lang/Exception.html)<br>An unexpected internal error occurred in Astronomy Engine |
| [InvalidBodyException](-invalid-body-exception/index.md)<br>class [InvalidBodyException](-invalid-body-exception/index.md)(body: [Body](-body/index.md)) : [Exception](https://docs.oracle.com/javase/8/docs/api/java/lang/Exception.html)<br>An invalid body was specified for the given function. |
| [JupiterMoonsInfo](-jupiter-moons-info/index.md)<br>class [JupiterMoonsInfo](-jupiter-moons-info/index.md)(io: [StateVector](-state-vector/index.md), europa: [StateVector](-state-vector/index.md), ganymede: [StateVector](-state-vector/index.md), callisto: [StateVector](-state-vector/index.md))<br>Holds the positions and velocities of Jupiter's major 4 moons. |
| [LibrationInfo](-libration-info/index.md)<br>data class [LibrationInfo](-libration-info/index.md)(elat: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), elon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), mlat: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), mlon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), distanceKm: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), diamDeg: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Lunar libration angles, returned by [libration](libration.md). |
| [LocalSolarEclipseInfo](-local-solar-eclipse-info/index.md)<br>class [LocalSolarEclipseInfo](-local-solar-eclipse-info/index.md)(kind: [EclipseKind](-eclipse-kind/index.md), obscuration: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), partialBegin: [EclipseEvent](-eclipse-event/index.md), totalBegin: [EclipseEvent](-eclipse-event/index.md)?, peak: [EclipseEvent](-eclipse-event/index.md), totalEnd: [EclipseEvent](-eclipse-event/index.md)?, partialEnd: [EclipseEvent](-eclipse-event/index.md))<br>Information about a solar eclipse as seen by an observer at a given time and geographic location. |
| [LunarEclipseInfo](-lunar-eclipse-info/index.md)<br>class [LunarEclipseInfo](-lunar-eclipse-info/index.md)(kind: [EclipseKind](-eclipse-kind/index.md), obscuration: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), peak: [Time](-time/index.md), sdPenum: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), sdPartial: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), sdTotal: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Information about a lunar eclipse. |
| [MoonQuarterInfo](-moon-quarter-info/index.md)<br>class [MoonQuarterInfo](-moon-quarter-info/index.md)(quarter: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), time: [Time](-time/index.md))<br>A lunar quarter event (new moon, first quarter, full moon, or third quarter) along with its date and time. |
| [NodeEventInfo](-node-event-info/index.md)<br>class [NodeEventInfo](-node-event-info/index.md)(time: [Time](-time/index.md), kind: [NodeEventKind](-node-event-kind/index.md))<br>Information about an ascending or descending node of a body. |
| [NodeEventKind](-node-event-kind/index.md)<br>enum [NodeEventKind](-node-event-kind/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[NodeEventKind](-node-event-kind/index.md)&gt; <br>Indicates whether a crossing through the ecliptic plane is ascending or descending. |
| [Observer](-observer/index.md)<br>data class [Observer](-observer/index.md)(latitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), longitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), height: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>The location of an observer on (or near) the surface of the Earth. |
| [PositionFunction](-position-function/index.md)<br>fun interface [PositionFunction](-position-function/index.md)<br>A function for which to solve a light-travel time problem. |
| [Refraction](-refraction/index.md)<br>enum [Refraction](-refraction/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[Refraction](-refraction/index.md)&gt; <br>Selects whether to correct for atmospheric refraction, and if so, how. |
| [RotationMatrix](-rotation-matrix/index.md)<br>class [RotationMatrix](-rotation-matrix/index.md)(rot: [Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)&lt;[DoubleArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double-array/index.html)&gt;)<br>A rotation matrix that can be used to transform one coordinate system to another. |
| [SearchContext](-search-context/index.md)<br>fun interface [SearchContext](-search-context/index.md)<br>Represents a function whose ascending root is to be found. |
| [SeasonsInfo](-seasons-info/index.md)<br>class [SeasonsInfo](-seasons-info/index.md)(marchEquinox: [Time](-time/index.md), juneSolstice: [Time](-time/index.md), septemberEquinox: [Time](-time/index.md), decemberSolstice: [Time](-time/index.md))<br>The dates and times of changes of season for a given calendar year. |
| [Spherical](-spherical/index.md)<br>data class [Spherical](-spherical/index.md)(lat: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), lon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dist: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Spherical coordinates: latitude, longitude, distance. |
| [StateVector](-state-vector/index.md)<br>data class [StateVector](-state-vector/index.md)(x: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), y: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), z: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), vx: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), vy: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), vz: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), t: [Time](-time/index.md))<br>Represents a combined position vector and velocity vector at a given moment in time. |
| [Time](-time/index.md)<br>class [Time](-time/index.md) : [Comparable](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-comparable/index.html)&lt;[Time](-time/index.md)&gt; <br>A date and time used for astronomical calculations. |
| [Topocentric](-topocentric/index.md)<br>data class [Topocentric](-topocentric/index.md)(azimuth: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), altitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Coordinates of a celestial body as seen by a topocentric observer. |
| [TransitInfo](-transit-info/index.md)<br>class [TransitInfo](-transit-info/index.md)(start: [Time](-time/index.md), peak: [Time](-time/index.md), finish: [Time](-time/index.md), separation: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Information about a transit of Mercury or Venus, as seen from the Earth. |
| [Vector](-vector/index.md)<br>data class [Vector](-vector/index.md)(x: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), y: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), z: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), t: [Time](-time/index.md))<br>A 3D Cartesian vector whose components are expressed in Astronomical Units (AU). |
| [Visibility](-visibility/index.md)<br>enum [Visibility](-visibility/index.md) : [Enum](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-enum/index.html)&lt;[Visibility](-visibility/index.md)&gt; <br>Indicates whether a body (especially Mercury or Venus) is best seen in the morning or evening. |

## Functions

| Name | Summary |
|---|---|
| [angleFromSun](angle-from-sun.md)<br>fun [angleFromSun](angle-from-sun.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Returns the angle between the given body and the Sun, as seen from the Earth. |
| [atmosphere](atmosphere.md)<br>fun [atmosphere](atmosphere.md)(elevationMeters: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [AtmosphereInfo](-atmosphere-info/index.md)<br>Calculates U.S. Standard Atmosphere (1976) variables as a function of elevation. |
| [backdatePosition](backdate-position.md)<br>fun [backdatePosition](backdate-position.md)(time: [Time](-time/index.md), observerBody: [Body](-body/index.md), targetBody: [Body](-body/index.md), aberration: [Aberration](-aberration/index.md)): [Vector](-vector/index.md)<br>Solve for light travel time correction of apparent position. |
| [baryState](bary-state.md)<br>fun [baryState](bary-state.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [StateVector](-state-vector/index.md)<br>Calculates barycentric position and velocity vectors for the given body. |
| [constellation](constellation.md)<br>fun [constellation](constellation.md)(ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [ConstellationInfo](-constellation-info/index.md)<br>Determines the constellation that contains the given point in the sky. |
| [correctLightTravel](correct-light-travel.md)<br>fun [correctLightTravel](correct-light-travel.md)(func: [PositionFunction](-position-function/index.md), time: [Time](-time/index.md)): [Vector](-vector/index.md)<br>Solve for light travel time of a vector function. |
| [defineStar](define-star.md)<br>fun [defineStar](define-star.md)(body: [Body](-body/index.md), ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), distanceLightYears: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html))<br>Assign equatorial coordinates to a user-defined star. |
| [degreesToRadians](degrees-to-radians.md)<br>fun [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html).[degreesToRadians](degrees-to-radians.md)(): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Convert an angle expressed in degrees to an angle expressed in radians. |
| [eclipticGeoMoon](ecliptic-geo-moon.md)<br>fun [eclipticGeoMoon](ecliptic-geo-moon.md)(time: [Time](-time/index.md)): [Spherical](-spherical/index.md)<br>Calculates spherical ecliptic geocentric position of the Moon. |
| [eclipticLongitude](ecliptic-longitude.md)<br>fun [eclipticLongitude](ecliptic-longitude.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates heliocentric ecliptic longitude of a body. |
| [elongation](elongation.md)<br>fun [elongation](elongation.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [ElongationInfo](-elongation-info/index.md)<br>Determines visibility of a celestial body relative to the Sun, as seen from the Earth. |
| [equator](equator.md)<br>fun [equator](equator.md)(body: [Body](-body/index.md), time: [Time](-time/index.md), observer: [Observer](-observer/index.md), equdate: [EquatorEpoch](-equator-epoch/index.md), aberration: [Aberration](-aberration/index.md)): [Equatorial](-equatorial/index.md)<br>Calculates equatorial coordinates of a celestial body as seen by an observer on the Earth's surface. |
| [equatorialToEcliptic](equatorial-to-ecliptic.md)<br>fun [equatorialToEcliptic](equatorial-to-ecliptic.md)(eqj: [Vector](-vector/index.md)): [Ecliptic](-ecliptic/index.md)<br>Converts a J2000 mean equator (EQJ) vector to a true ecliptic of date (ETC) vector and angles. |
| [geoEmbState](geo-emb-state.md)<br>fun [geoEmbState](geo-emb-state.md)(time: [Time](-time/index.md)): [StateVector](-state-vector/index.md)<br>Calculates the geocentric position and velocity of the Earth/Moon barycenter. |
| [geoMoon](geo-moon.md)<br>fun [geoMoon](geo-moon.md)(time: [Time](-time/index.md)): [Vector](-vector/index.md)<br>Calculates equatorial geocentric position of the Moon at a given time. |
| [geoMoonState](geo-moon-state.md)<br>fun [geoMoonState](geo-moon-state.md)(time: [Time](-time/index.md)): [StateVector](-state-vector/index.md)<br>Calculates equatorial geocentric position and velocity of the Moon at a given time. |
| [geoVector](geo-vector.md)<br>fun [geoVector](geo-vector.md)(body: [Body](-body/index.md), time: [Time](-time/index.md), aberration: [Aberration](-aberration/index.md)): [Vector](-vector/index.md)<br>Calculates geocentric Cartesian coordinates of a body in the J2000 equatorial system. |
| [globalSolarEclipsesAfter](global-solar-eclipses-after.md)<br>fun [globalSolarEclipsesAfter](global-solar-eclipses-after.md)(startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[GlobalSolarEclipseInfo](-global-solar-eclipse-info/index.md)&gt;<br>Enumerates a series of consecutive global solar eclipses that occur after a given time. |
| [helioDistance](helio-distance.md)<br>fun [helioDistance](helio-distance.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates the distance between a body and the Sun at a given time. |
| [helioState](helio-state.md)<br>fun [helioState](helio-state.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [StateVector](-state-vector/index.md)<br>Calculates heliocentric position and velocity vectors for the given body. |
| [helioVector](helio-vector.md)<br>fun [helioVector](helio-vector.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [Vector](-vector/index.md)<br>Calculates heliocentric Cartesian coordinates of a body in the J2000 equatorial system. |
| [horizon](horizon.md)<br>fun [horizon](horizon.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md), ra: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), dec: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), refraction: [Refraction](-refraction/index.md)): [Topocentric](-topocentric/index.md)<br>Calculates the apparent location of a body relative to the local horizon of an observer on the Earth. |
| [hourAngle](hour-angle.md)<br>fun [hourAngle](hour-angle.md)(body: [Body](-body/index.md), time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Finds the hour angle of a body for a given observer and time. |
| [illumination](illumination.md)<br>fun [illumination](illumination.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [IlluminationInfo](-illumination-info/index.md)<br>Finds visual magnitude, phase angle, and other illumination information about a celestial body. |
| [inverseRefractionAngle](inverse-refraction-angle.md)<br>fun [inverseRefractionAngle](inverse-refraction-angle.md)(refraction: [Refraction](-refraction/index.md), bentAltitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates the inverse of an atmospheric refraction angle. |
| [jupiterMoons](jupiter-moons.md)<br>fun [jupiterMoons](jupiter-moons.md)(time: [Time](-time/index.md)): [JupiterMoonsInfo](-jupiter-moons-info/index.md)<br>Calculates jovicentric positions and velocities of Jupiter's largest 4 moons. |
| [lagrangePoint](lagrange-point.md)<br>fun [lagrangePoint](lagrange-point.md)(point: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), time: [Time](-time/index.md), majorBody: [Body](-body/index.md), minorBody: [Body](-body/index.md)): [StateVector](-state-vector/index.md)<br>Calculates one of the 5 Lagrange points for a pair of co-orbiting bodies. |
| [lagrangePointFast](lagrange-point-fast.md)<br>fun [lagrangePointFast](lagrange-point-fast.md)(point: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html), majorState: [StateVector](-state-vector/index.md), majorMass: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), minorState: [StateVector](-state-vector/index.md), minorMass: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [StateVector](-state-vector/index.md)<br>Calculates one of the 5 Lagrange points from body masses and state vectors. |
| [libration](libration.md)<br>fun [libration](libration.md)(time: [Time](-time/index.md)): [LibrationInfo](-libration-info/index.md)<br>Calculates the Moon's libration angles at a given moment in time. |
| [localSolarEclipsesAfter](local-solar-eclipses-after.md)<br>fun [localSolarEclipsesAfter](local-solar-eclipses-after.md)(startTime: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[LocalSolarEclipseInfo](-local-solar-eclipse-info/index.md)&gt;<br>Enumerates a series of consecutive local solar eclipses that occur after a given time. |
| [lunarApsidesAfter](lunar-apsides-after.md)<br>fun [lunarApsidesAfter](lunar-apsides-after.md)(startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[ApsisInfo](-apsis-info/index.md)&gt;<br>Enumerates a series of consecutive lunar apsides that occur after a given time. |
| [lunarEclipsesAfter](lunar-eclipses-after.md)<br>fun [lunarEclipsesAfter](lunar-eclipses-after.md)(startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[LunarEclipseInfo](-lunar-eclipse-info/index.md)&gt;<br>Enumerates a series of consecutive lunar eclipses that occur after a given time. |
| [massProduct](mass-product.md)<br>fun [massProduct](mass-product.md)(body: [Body](-body/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Returns the product of mass and universal gravitational constant of a Solar System body. |
| [moonNodesAfter](moon-nodes-after.md)<br>fun [moonNodesAfter](moon-nodes-after.md)(startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[NodeEventInfo](-node-event-info/index.md)&gt;<br>Enumerates a series of consecutive ascending/descending nodes of the Moon. |
| [moonPhase](moon-phase.md)<br>fun [moonPhase](moon-phase.md)(time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Returns the Moon's phase as an angle from 0 to 360 degrees. |
| [moonQuartersAfter](moon-quarters-after.md)<br>fun [moonQuartersAfter](moon-quarters-after.md)(startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[MoonQuarterInfo](-moon-quarter-info/index.md)&gt;<br>Enumerates a series of consecutive moon quarter phase events. |
| [nextGlobalSolarEclipse](next-global-solar-eclipse.md)<br>fun [nextGlobalSolarEclipse](next-global-solar-eclipse.md)(prevEclipseTime: [Time](-time/index.md)): [GlobalSolarEclipseInfo](-global-solar-eclipse-info/index.md)<br>Searches for the next global solar eclipse in a series. |
| [nextLocalSolarEclipse](next-local-solar-eclipse.md)<br>fun [nextLocalSolarEclipse](next-local-solar-eclipse.md)(prevEclipseTime: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [LocalSolarEclipseInfo](-local-solar-eclipse-info/index.md)<br>Searches for the next local solar eclipse in a series. |
| [nextLunarApsis](next-lunar-apsis.md)<br>fun [nextLunarApsis](next-lunar-apsis.md)(apsis: [ApsisInfo](-apsis-info/index.md)): [ApsisInfo](-apsis-info/index.md)<br>Finds the next lunar perigee or apogee event in a series. |
| [nextLunarEclipse](next-lunar-eclipse.md)<br>fun [nextLunarEclipse](next-lunar-eclipse.md)(prevEclipseTime: [Time](-time/index.md)): [LunarEclipseInfo](-lunar-eclipse-info/index.md)<br>Searches for the next lunar eclipse in a series. |
| [nextMoonNode](next-moon-node.md)<br>fun [nextMoonNode](next-moon-node.md)(prevNode: [NodeEventInfo](-node-event-info/index.md)): [NodeEventInfo](-node-event-info/index.md)<br>Searches for the next time when the Moon's center crosses through the ecliptic plane. |
| [nextMoonQuarter](next-moon-quarter.md)<br>fun [nextMoonQuarter](next-moon-quarter.md)(mq: [MoonQuarterInfo](-moon-quarter-info/index.md)): [MoonQuarterInfo](-moon-quarter-info/index.md)<br>Continues searching for lunar quarters from a previous search. |
| [nextPlanetApsis](next-planet-apsis.md)<br>fun [nextPlanetApsis](next-planet-apsis.md)(body: [Body](-body/index.md), apsis: [ApsisInfo](-apsis-info/index.md)): [ApsisInfo](-apsis-info/index.md)<br>Finds the next planetary perihelion or aphelion event in a series. |
| [nextTransit](next-transit.md)<br>fun [nextTransit](next-transit.md)(body: [Body](-body/index.md), prevTransitTime: [Time](-time/index.md)): [TransitInfo](-transit-info/index.md)<br>Searches for another transit of Mercury or Venus. |
| [observerGravity](observer-gravity.md)<br>fun [observerGravity](observer-gravity.md)(latitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), height: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates the gravitational acceleration experienced by an observer on the Earth. |
| [pairLongitude](pair-longitude.md)<br>fun [pairLongitude](pair-longitude.md)(body1: [Body](-body/index.md), body2: [Body](-body/index.md), time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Returns one body's ecliptic longitude with respect to another, as seen from the Earth. |
| [planetApsidesAfter](planet-apsides-after.md)<br>fun [planetApsidesAfter](planet-apsides-after.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[ApsisInfo](-apsis-info/index.md)&gt;<br>Enumerates a series of consecutive planetary perihelia/aphelia events. |
| [planetOrbitalPeriod](planet-orbital-period.md)<br>fun [planetOrbitalPeriod](planet-orbital-period.md)(body: [Body](-body/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Returns the average number of days it takes for a planet to orbit the Sun. |
| [radiansToDegrees](radians-to-degrees.md)<br>fun [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html).[radiansToDegrees](radians-to-degrees.md)(): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Convert an angle expressed in radians to an angle expressed in degrees. |
| [refractionAngle](refraction-angle.md)<br>fun [refractionAngle](refraction-angle.md)(refraction: [Refraction](-refraction/index.md), altitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates the amount of "lift" to an altitude angle caused by atmospheric refraction. |
| [rotationAxis](rotation-axis.md)<br>fun [rotationAxis](rotation-axis.md)(body: [Body](-body/index.md), time: [Time](-time/index.md)): [AxisInfo](-axis-info/index.md)<br>Calculates information about a body's rotation axis at a given time. |
| [rotationEclEqd](rotation-ecl-eqd.md)<br>fun [rotationEclEqd](rotation-ecl-eqd.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean ecliptic (ECL) to equatorial of-date (EQD). |
| [rotationEclEqj](rotation-ecl-eqj.md)<br>fun [rotationEclEqj](rotation-ecl-eqj.md)(): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean ecliptic (ECL) to J2000 mean equator (EQJ). |
| [rotationEclHor](rotation-ecl-hor.md)<br>fun [rotationEclHor](rotation-ecl-hor.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean ecliptic (ECL) to horizontal (HOR). |
| [rotationEctEqd](rotation-ect-eqd.md)<br>fun [rotationEctEqd](rotation-ect-eqd.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from true ecliptic of date (ECT) to equator of date (EQD). |
| [rotationEctEqj](rotation-ect-eqj.md)<br>fun [rotationEctEqj](rotation-ect-eqj.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from true ecliptic of date (ECT) to J2000 mean equator (EQJ). |
| [rotationEqdEcl](rotation-eqd-ecl.md)<br>fun [rotationEqdEcl](rotation-eqd-ecl.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from equatorial of-date (EQD) to J2000 mean ecliptic (ECL). |
| [rotationEqdEct](rotation-eqd-ect.md)<br>fun [rotationEqdEct](rotation-eqd-ect.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from equator of date (EQD) to true ecliptic of date (ECT). |
| [rotationEqdEqj](rotation-eqd-eqj.md)<br>fun [rotationEqdEqj](rotation-eqd-eqj.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from equatorial of-date (EQD) to J2000 mean equator (EQJ). |
| [rotationEqdHor](rotation-eqd-hor.md)<br>fun [rotationEqdHor](rotation-eqd-hor.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from equatorial of-date (EQD) to horizontal (HOR). |
| [rotationEqjEcl](rotation-eqj-ecl.md)<br>fun [rotationEqjEcl](rotation-eqj-ecl.md)(): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean equator (EQJ) to J2000 mean ecliptic (ECL). |
| [rotationEqjEct](rotation-eqj-ect.md)<br>fun [rotationEqjEct](rotation-eqj-ect.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean equator (EQJ) to true ecliptic of date (ECT). |
| [rotationEqjEqd](rotation-eqj-eqd.md)<br>fun [rotationEqjEqd](rotation-eqj-eqd.md)(time: [Time](-time/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean equator (EQJ) to equatorial of-date (EQD). |
| [rotationEqjGal](rotation-eqj-gal.md)<br>fun [rotationEqjGal](rotation-eqj-gal.md)(): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from galactic (GAL) to J2000 mean equator (EQJ). |
| [rotationEqjHor](rotation-eqj-hor.md)<br>fun [rotationEqjHor](rotation-eqj-hor.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from J2000 mean equator (EQJ) to horizontal (HOR). |
| [rotationGalEqj](rotation-gal-eqj.md)<br>fun [rotationGalEqj](rotation-gal-eqj.md)(): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from galactic (GAL) to J2000 mean equator (EQJ). |
| [rotationHorEcl](rotation-hor-ecl.md)<br>fun [rotationHorEcl](rotation-hor-ecl.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from horizontal (HOR) to J2000 mean ecliptic (ECL). |
| [rotationHorEqd](rotation-hor-eqd.md)<br>fun [rotationHorEqd](rotation-hor-eqd.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from horizontal (HOR) to equatorial of-date (EQD). |
| [rotationHorEqj](rotation-hor-eqj.md)<br>fun [rotationHorEqj](rotation-hor-eqj.md)(time: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [RotationMatrix](-rotation-matrix/index.md)<br>Calculates a rotation matrix from horizontal (HOR) to J2000 equatorial (EQJ). This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: HOR = horizontal system (x=North, y=West, z=Zenith). Target: EQJ = equatorial system, using equator at the J2000 epoch. |
| [search](search.md)<br>fun [search](search.md)(time1: [Time](-time/index.md), time2: [Time](-time/index.md), toleranceSeconds: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), func: [SearchContext](-search-context/index.md)): [Time](-time/index.md)?<br>Searches for a time at which a function's value increases through zero. |
| [searchAltitude](search-altitude.md)<br>fun [searchAltitude](search-altitude.md)(body: [Body](-body/index.md), observer: [Observer](-observer/index.md), direction: [Direction](-direction/index.md), startTime: [Time](-time/index.md), limitDays: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), altitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Time](-time/index.md)?<br>Finds the next time the center of a body reaches a given altitude. |
| [searchGlobalSolarEclipse](search-global-solar-eclipse.md)<br>fun [searchGlobalSolarEclipse](search-global-solar-eclipse.md)(startTime: [Time](-time/index.md)): [GlobalSolarEclipseInfo](-global-solar-eclipse-info/index.md)<br>Searches for a solar eclipse visible anywhere on the Earth's surface. |
| [searchHourAngle](search-hour-angle.md)<br>fun [searchHourAngle](search-hour-angle.md)(body: [Body](-body/index.md), observer: [Observer](-observer/index.md), hourAngle: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), startTime: [Time](-time/index.md), direction: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) = +1): [HourAngleInfo](-hour-angle-info/index.md)<br>Searches for the time when the center of a body reaches a specified hour angle as seen by an observer on the Earth. |
| [searchLocalSolarEclipse](search-local-solar-eclipse.md)<br>fun [searchLocalSolarEclipse](search-local-solar-eclipse.md)(startTime: [Time](-time/index.md), observer: [Observer](-observer/index.md)): [LocalSolarEclipseInfo](-local-solar-eclipse-info/index.md)<br>Searches for a solar eclipse visible at a specific location on the Earth's surface. |
| [searchLunarApsis](search-lunar-apsis.md)<br>fun [searchLunarApsis](search-lunar-apsis.md)(startTime: [Time](-time/index.md)): [ApsisInfo](-apsis-info/index.md)<br>Finds the date and time of the Moon's perigee or apogee. |
| [searchLunarEclipse](search-lunar-eclipse.md)<br>fun [searchLunarEclipse](search-lunar-eclipse.md)(startTime: [Time](-time/index.md)): [LunarEclipseInfo](-lunar-eclipse-info/index.md)<br>Searches for a lunar eclipse. |
| [searchMaxElongation](search-max-elongation.md)<br>fun [searchMaxElongation](search-max-elongation.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [ElongationInfo](-elongation-info/index.md)<br>Finds a date and time when Mercury or Venus reaches its maximum angle from the Sun as seen from the Earth. |
| [searchMoonNode](search-moon-node.md)<br>fun [searchMoonNode](search-moon-node.md)(startTime: [Time](-time/index.md)): [NodeEventInfo](-node-event-info/index.md)<br>Searches for a time when the Moon's center crosses through the ecliptic plane. |
| [searchMoonPhase](search-moon-phase.md)<br>fun [searchMoonPhase](search-moon-phase.md)(targetLon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), startTime: [Time](-time/index.md), limitDays: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Time](-time/index.md)?<br>Searches for the time that the Moon reaches a specified phase. |
| [searchMoonQuarter](search-moon-quarter.md)<br>fun [searchMoonQuarter](search-moon-quarter.md)(startTime: [Time](-time/index.md)): [MoonQuarterInfo](-moon-quarter-info/index.md)<br>Finds the first lunar quarter after the specified date and time. A lunar quarter is one of the following four lunar phase events: new moon, first quarter, full moon, third quarter. This function finds the lunar quarter that happens soonest after the specified date and time. |
| [searchPeakMagnitude](search-peak-magnitude.md)<br>fun [searchPeakMagnitude](search-peak-magnitude.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [IlluminationInfo](-illumination-info/index.md)<br>Searches for the date and time Venus will next appear brightest as seen from the Earth. |
| [searchPlanetApsis](search-planet-apsis.md)<br>fun [searchPlanetApsis](search-planet-apsis.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [ApsisInfo](-apsis-info/index.md)<br>Finds the first aphelion or perihelion for a planet after a given time. |
| [searchRelativeLongitude](search-relative-longitude.md)<br>fun [searchRelativeLongitude](search-relative-longitude.md)(body: [Body](-body/index.md), targetRelativeLongitude: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), startTime: [Time](-time/index.md)): [Time](-time/index.md)<br>Searches for the time when the Earth and another planet are separated by a specified angle in ecliptic longitude, as seen from the Sun. |
| [searchRiseSet](search-rise-set.md)<br>@[JvmOverloads](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.jvm/-jvm-overloads/index.html)<br>fun [searchRiseSet](search-rise-set.md)(body: [Body](-body/index.md), observer: [Observer](-observer/index.md), direction: [Direction](-direction/index.md), startTime: [Time](-time/index.md), limitDays: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), metersAboveGround: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 0.0): [Time](-time/index.md)?<br>Searches for the next time a celestial body rises or sets as seen by an observer on the Earth. |
| [searchSunLongitude](search-sun-longitude.md)<br>fun [searchSunLongitude](search-sun-longitude.md)(targetLon: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html), startTime: [Time](-time/index.md), limitDays: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [Time](-time/index.md)?<br>Searches for the time when the Sun reaches an apparent ecliptic longitude as seen from the Earth. |
| [searchTransit](search-transit.md)<br>fun [searchTransit](search-transit.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [TransitInfo](-transit-info/index.md)<br>Searches for the first transit of Mercury or Venus after a given date. |
| [seasons](seasons.md)<br>fun [seasons](seasons.md)(year: [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)): [SeasonsInfo](-seasons-info/index.md)<br>Finds both equinoxes and both solstices for a given calendar year. |
| [siderealTime](sidereal-time.md)<br>fun [siderealTime](sidereal-time.md)(time: [Time](-time/index.md)): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>Calculates Greenwich Apparent Sidereal Time (GAST). |
| [sunPosition](sun-position.md)<br>fun [sunPosition](sun-position.md)(time: [Time](-time/index.md)): [Ecliptic](-ecliptic/index.md)<br>Calculates geocentric ecliptic coordinates for the Sun. |
| [times](times.md)<br>operator fun [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html).[times](times.md)(vec: [Vector](-vector/index.md)): [Vector](-vector/index.md)<br>Multiply a scalar by a vector, yielding another vector. |
| [transitsAfter](transits-after.md)<br>fun [transitsAfter](transits-after.md)(body: [Body](-body/index.md), startTime: [Time](-time/index.md)): [Sequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/-sequence/index.html)&lt;[TransitInfo](-transit-info/index.md)&gt;<br>Enumerates a series of consecutive transits of Mercury or Venus. |

## Properties

| Name | Summary |
|---|---|
| [AU_PER_LY](-a-u_-p-e-r_-l-y.md)<br>const val [AU_PER_LY](-a-u_-p-e-r_-l-y.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 63241.07708807546<br>The number of astronomical units per light-year. |
| [C_AUDAY](-c_-a-u-d-a-y.md)<br>const val [C_AUDAY](-c_-a-u-d-a-y.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 173.1446326846693<br>The speed of light in AU/day. |
| [CALLISTO_RADIUS_KM](-c-a-l-l-i-s-t-o_-r-a-d-i-u-s_-k-m.md)<br>const val [CALLISTO_RADIUS_KM](-c-a-l-l-i-s-t-o_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 2410.3<br>The mean radius of Jupiter's moon Callisto, expressed in kilometers. |
| [DEG2RAD](-d-e-g2-r-a-d.md)<br>const val [DEG2RAD](-d-e-g2-r-a-d.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 0.017453292519943295<br>The factor to convert degrees to radians = pi/180. |
| [EUROPA_RADIUS_KM](-e-u-r-o-p-a_-r-a-d-i-u-s_-k-m.md)<br>const val [EUROPA_RADIUS_KM](-e-u-r-o-p-a_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 1560.8<br>The mean radius of Jupiter's moon Europa, expressed in kilometers. |
| [GANYMEDE_RADIUS_KM](-g-a-n-y-m-e-d-e_-r-a-d-i-u-s_-k-m.md)<br>const val [GANYMEDE_RADIUS_KM](-g-a-n-y-m-e-d-e_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 2631.2<br>The mean radius of Jupiter's moon Ganymede, expressed in kilometers. |
| [HOUR2RAD](-h-o-u-r2-r-a-d.md)<br>const val [HOUR2RAD](-h-o-u-r2-r-a-d.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 0.26179938779914946<br>The factor to convert sidereal hours to radians = pi/12. |
| [IO_RADIUS_KM](-i-o_-r-a-d-i-u-s_-k-m.md)<br>const val [IO_RADIUS_KM](-i-o_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 1821.6<br>The mean radius of Jupiter's moon Io, expressed in kilometers. |
| [JUPITER_EQUATORIAL_RADIUS_KM](-j-u-p-i-t-e-r_-e-q-u-a-t-o-r-i-a-l_-r-a-d-i-u-s_-k-m.md)<br>const val [JUPITER_EQUATORIAL_RADIUS_KM](-j-u-p-i-t-e-r_-e-q-u-a-t-o-r-i-a-l_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 71492.0<br>The equatorial radius of Jupiter, expressed in kilometers. |
| [JUPITER_MEAN_RADIUS_KM](-j-u-p-i-t-e-r_-m-e-a-n_-r-a-d-i-u-s_-k-m.md)<br>const val [JUPITER_MEAN_RADIUS_KM](-j-u-p-i-t-e-r_-m-e-a-n_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 69911.0<br>The volumetric mean radius of Jupiter, expressed in kilometers. |
| [JUPITER_POLAR_RADIUS_KM](-j-u-p-i-t-e-r_-p-o-l-a-r_-r-a-d-i-u-s_-k-m.md)<br>const val [JUPITER_POLAR_RADIUS_KM](-j-u-p-i-t-e-r_-p-o-l-a-r_-r-a-d-i-u-s_-k-m.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 66854.0<br>The polar radius of Jupiter, expressed in kilometers. |
| [KM_PER_AU](-k-m_-p-e-r_-a-u.md)<br>const val [KM_PER_AU](-k-m_-p-e-r_-a-u.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 1.4959787069098932E8<br>The number of kilometers in one astronomical unit (AU). |
| [MILLISECONDS_PER_DAY](-m-i-l-l-i-s-e-c-o-n-d-s_-p-e-r_-d-a-y.md)<br>const val [MILLISECONDS_PER_DAY](-m-i-l-l-i-s-e-c-o-n-d-s_-p-e-r_-d-a-y.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>The number of milliseconds in a day. |
| [MINUTES_PER_DAY](-m-i-n-u-t-e-s_-p-e-r_-d-a-y.md)<br>const val [MINUTES_PER_DAY](-m-i-n-u-t-e-s_-p-e-r_-d-a-y.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>The number of minutes in a day. |
| [RAD2DEG](-r-a-d2-d-e-g.md)<br>const val [RAD2DEG](-r-a-d2-d-e-g.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 57.29577951308232<br>The factor to convert radians to degrees = 180/pi. |
| [RAD2HOUR](-r-a-d2-h-o-u-r.md)<br>const val [RAD2HOUR](-r-a-d2-h-o-u-r.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) = 3.819718634205488<br>The factor to convert radians to sidereal hours = 12/pi. |
| [SECONDS_PER_DAY](-s-e-c-o-n-d-s_-p-e-r_-d-a-y.md)<br>const val [SECONDS_PER_DAY](-s-e-c-o-n-d-s_-p-e-r_-d-a-y.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)<br>The number of seconds in a day. |