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Planet Class

Note: This API is now obsolete.

NOVAS-COM: Provide characteristics of a solar system body
Inheritance Hierarchy
SystemObject
  ASCOM.Astrometry.NOVASCOMPlanet

Namespace: ASCOM.Astrometry.NOVASCOM
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.2.0.2774)
Syntax
[ObsoleteAttribute("This class will be withdrawn in the next major release, please use the SOFA or NOVAS31 classes instead")]
public class Planet

The Planet type exposes the following members.

Constructors
  NameDescription
Public methodPlanet
Create a new instance of the Plant class
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Properties
  NameDescription
Public propertyDeltaT
Planet delta-T
Public propertyEarthEphemeris
Ephemeris object used to provide the position of the Earth.
Public propertyEphemeris
The Ephemeris object used to provide positions of solar system bodies.
Public propertyName
Planet name
Public propertyNumber
Planet number
Public propertyType
The type of solar system body
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Methods
  NameDescription
Public methodGetApparentPosition
Get an apparent position for given time
Public methodGetAstrometricPosition
Get an astrometric position for given time
Public methodGetLocalPosition
Get an local position for given time
Public methodGetTopocentricPosition
Get a topocentric position for given time
Public methodGetVirtualPosition
Get a virtual position for given time
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Remarks
NOVAS-COM objects of class Planet hold the characteristics of a solar system body. Properties are type (major or minor planet), number (for major and numbered minor planets), name (for unnumbered minor planets and comets), the ephemeris object to be used for orbital calculations, an optional ephemeris object to use for barycenter calculations, and an optional value for delta-T.

The number values for major planets are 1 to 9 for Mercury to Pluto, 10 for Sun and 11 for Moon. The last two obviously aren't planets, but this numbering is a NOVAS convention that enables us to retrieve useful information about these bodies.

The high-level NOVAS astrometric functions are implemented as methods of Planet: GetTopocentricPosition(), GetLocalPosition(), GetApparentPosition(), GetVirtualPosition(), and GetAstrometricPosition(). These methods operate on the properties of the Planet, and produce a PositionVector object. For example, to get the topocentric coordinates of a planet, create and initialize a planet then call Planet.GetTopocentricPosition(). The resulting PositionVector's right ascension and declination properties are the topocentric equatorial coordinates, at the same time, the (optionally refracted) alt-az coordinates are calculated, and are also contained within the returned PositionVector. Note that Alt/Az is available in PositionVectors returned from calling GetTopocentricPosition(). The accuracy of these calculations is typically dominated by the accuracy of the attached ephemeris generator.

Ephemeris Generator
By default, Kepler instances are attached for both Earth and Planet objects so it is not necessary to create and attach these in order to get Kepler accuracy from this component

The ephemeris generator object used with NOVAS-COM must support a single method GetPositionAndVelocity(tjd). This method must take a terrestrial Julian date (like the NOVAS-COM methods) as its single parameter, and return an array of Double containing the rectangular (x/y/z) heliocentric J2000 equatorial coordinates of position (AU) and velocity (KM/sec.). In addition, it must support three read/write properties BodyType, Name, and Number, which correspond to the Type, Name, and Number properties of Novas.Planet.

See Also