slaSubet -
SYNOPSYS
void slaSubet(rc, dc, eq, rm, dm)
PARAMETERS
- double rc
-
- double dc
-
- double eq
-
- double *rm
-
- double *dm
-
DESCRIPTION
Remove the e-terms (elliptic component of annual aberration)
from a pre IAU 1976 catalogue RA,Dec to give a mean place.
(double precision)
Given
rc,dc double RA,Dec (radians) with e-terms included
eq double Besselian epoch of mean equator and equinox
Returned
*rm,*dm double RA,Dec (radians) without e-terms
Called
slaEtrms, slaDcs2c, sla,dvdv, slaDcc2s, slaDranrm
Explanation
Most star positions from pre-1984 optical catalogues (or
derived from astrometry using such stars) embody the
e-terms. This routine converts such a position to a
formal mean place (allowing, for example, comparison with a
pulsar timing position).
Reference
Explanatory Supplement to the Astronomical Ephemeris,
section 2D, page 48.
P.T.Wallace Starlink 31 October 1993
SEE ALSO