era.h2fk5.md

eraH2fk5

[r5, d5, dr5, dd5, px5, rv5] = ERFA.h2fk5(rh, dh, drh, ddh, pxh, rvh)

Transform Hipparcos star data into the FK5 (J2000.0) system.

Given (all Hipparcos, epoch J2000.0):

   rh      double    RA (radians)
   dh      double    Dec (radians)
   drh     double    proper motion in RA (dRA/dt, rad/Jyear)
   ddh     double    proper motion in Dec (dDec/dt, rad/Jyear)
   pxh     double    parallax (arcsec)
   rvh     double    radial velocity (km/s, positive = receding)

Returned (all FK5, equinox J2000.0, epoch J2000.0):

   r5      double    RA (radians)
   d5      double    Dec (radians)
   dr5     double    proper motion in RA (dRA/dt, rad/Jyear)
   dd5     double    proper motion in Dec (dDec/dt, rad/Jyear)
   px5     double    parallax (arcsec)
   rv5     double    radial velocity (km/s, positive = receding)

Notes:

1. This function transforms Hipparcos star positions and proper motions into FK5 J2000.0.

2. The proper motions in RA are dRA/dt rather than cos(Dec)*dRA/dt, and are per year rather than per century.

3. The FK5 to Hipparcos transformation is modeled as a pure rotation and spin; zonal errors in the FK5 catalog are not taken into account.

4. See also eraFk52h, eraFk5hz, eraHfk5z.

Called:

   eraStarpv    star catalog data to space motion pv-vector
   eraFk5hip    FK5 to Hipparcos rotation and spin
   eraRv2m      r-vector to r-matrix
   eraRxp       product of r-matrix and p-vector
   eraTrxp      product of transpose of r-matrix and p-vector
   eraPxp       vector product of two p-vectors
   eraPmp       p-vector minus p-vector
   eraPvstar    space motion pv-vector to star catalog data

Reference:

F.Mignard & M.Froeschle, Astron.Astrophys., 354, 732-739 (2000).

This revision: 2021 May 11

Copyright (C) 2013-2021, NumFOCUS Foundation. Derived, with permission, from the SOFA library.