Convert Hipparcos catalog data at epoch J1991.25 to epoch J2000.0, for use within NOVAS.

Namespace: ASCOM.Astrometry.NOVAS
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.1.1.2619)

Syntax

C#
public void TransformHip(
	CatEntry3 Hipparcos,
	ref CatEntry3 Hip2000
)
Visual Basic
Public Sub TransformHip ( _
	Hipparcos As CatEntry3, _
	ByRef Hip2000 As CatEntry3 _
)
Visual C++
public:
virtual void TransformHip(
	CatEntry3 Hipparcos, 
	CatEntry3% Hip2000
) sealed

Parameters

Hipparcos
Type: ASCOM.Astrometry..::..CatEntry3
An entry from the Hipparcos catalog, at epoch J1991.25, with all members having Hipparcos catalog units. See Note 1 below
Hip2000
Type: ASCOM.Astrometry..::..CatEntry3%
The transformed input entry, at epoch J2000.0. See Note 2 below

Remarks

To be used only for Hipparcos or Tycho stars with linear space motion. Both input and output data is in the ICRS.

1. Input (Hipparcos catalog) epoch and units:

  • Epoch: J1991.25
  • Right ascension (RA): degrees
  • Declination (Dec): degrees
  • Proper motion in RA: milliarcseconds per year
  • Proper motion in Dec: milliarcseconds per year
  • Parallax: milliarcseconds
  • Radial velocity: kilometers per second (not in catalog)

2. Output (modified Hipparcos) epoch and units:

  • Epoch: J2000.0
  • Right ascension: hours
  • Declination: degrees
  • Proper motion in RA: milliarcseconds per year
  • Proper motion in Dec: milliarcseconds per year
  • Parallax: milliarcseconds
  • Radial velocity: kilometers per second
>

See Also