Star Class
NOVAS-COM: Star Class
Namespace: ASCOM.Tools.NovasComAssembly: ASCOM.AstrometryTools (in ASCOM.AstrometryTools.dll) Version: 2.2.1+77356f79b05b579f6d860a4edd5934fda9fe29e4
- Inheritance
- Object Star
NOVAS-COM objects of class Star contain the specifications for a star's catalog position in either FK5 or Hipparcos units (both must be J2000). Properties are right ascension and declination, proper motions, parallax, radial velocity, catalog type (FK5 or HIP), catalog number, optional ephemeris engine to use for barycenter calculations, and an optional value for delta-T. Unless you specifically set the DeltaT property, calculations performed by this class which require the value of delta-T (TT - UT1) rely on an internal function to estimate delta-T.
The high-level NOVAS astrometric functions are implemented as methods of Star:
GetTopocentricPosition(), GetLocalPosition(), GetApparentPosition(), GetVirtualPosition(),
and GetAstrometricPosition(). These methods operate on the properties of the Star, and produce
a PositionVector object. For example, to get the topocentric coordinates of a star, simply create
and initialize a Star, then call Star.GetTopocentricPosition(). The resulting vaPositionVector'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().
| Star |
Initialise a new instance of the star class
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| Star(ILogger) |
Initialise the star class with an ILogger instance to record debug information
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| Catalog |
Three character catalog code for the star's data
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| Declination |
Mean catalog J2000 declination coordinate (degrees)
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| DeltaT |
The value of delta-T (TT - UT1) to use for reductions.
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| EarthEphemeris |
Ephemeris object used to provide the position of the Earth.
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| Name |
The catalog name of the star (50 char max)
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| Number |
The catalog number of the star
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| Parallax |
Catalog mean J2000 parallax (arcsec)
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| ProperMotionDec |
Catalog mean J2000 proper motion in declination (arcsec/century)
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| ProperMotionRA |
Catalog mean J2000 proper motion in right ascension (sec/century)
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| RadialVelocity |
Catalog mean J2000 radial velocity (km/sec)
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| RightAscension |
Catalog mean J2000 right ascension coordinate (hours)
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| GetApparentPosition |
Get an apparent position for a given time
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| GetAstrometricPosition |
This is the NOVAS-COM implementation of astro_star(). See the
original NOVAS-C sources for more info.
Get an astrometric position for a given time
|
| GetEarth |
Obtains the barycentric and heliocentric positions and velocities of the Earth from the solar system ephemeris.
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| GetLocalPosition |
Get a local position for a given site and time
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| GetTopocentricPosition |
Get a topocentric position for a given site and time
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| GetVirtualPosition |
Get a virtual position at a given time
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| Set |
Initialize all star properties with one call
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| SetHipparcos |
Initialise all star properties in one call using Hipparcos data. Transforms to FK5 standard used by NOVAS.
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Supported in: 2.0
