To convert Hipparcos data at epoch J1991.25 to epoch J2000.0 and FK5-style units.

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


public void TransformHip(
	ref CatEntry hipparcos,
	ref CatEntry fk5
Visual Basic
Public Sub TransformHip ( _
	ByRef hipparcos As CatEntry, _
	ByRef fk5 As CatEntry _
Visual C++
virtual void TransformHip(
	CatEntry% hipparcos, 
	CatEntry% fk5
) sealed


Type: ASCOM.Astrometry..::..CatEntry%
An entry from the Hipparcos catalog, at epoch J1991.25, with all members having Hipparcos catalog units. See Note 1 below
Type: ASCOM.Astrometry..::..CatEntry%
The transformed input entry, at epoch J2000.0, with all members having FK5 catalog units. See Note 2 below


To be used only for Hipparcos or Tycho stars with linear space motion.

 1. Hipparcos epoch and units:
    Epoch: J1991.25
    Right ascension (RA): degrees
    Declination (Dec): degrees
    Proper motion in RA * cos (Dec): milliarcseconds per year
    Proper motion in Dec: milliarcseconds per year
    Parallax: milliarcseconds
    Radial velocity: kilometers per second (not in catalog)
 2. FK5 epoch and units:
    Epoch: J2000.0
    Right ascension: hours
    Declination: degrees
    Proper motion in RA: seconds of time per Julian century
    Proper motion in Dec: arcseconds per Julian century
    Parallax: arcseconds
    Radial velocity: kilometers per second

See Also