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.help etrms Jun99 "Slalib Package"
.nf
SUBROUTINE slETRM (EP, EV)
- - - - - -
E T R M
- - - - - -
Compute the E-terms (elliptic component of annual aberration)
vector (double precision)
Given:
EP dp Besselian epoch
Returned:
EV dp(3) E-terms as (dx,dy,dz)
Note the use of the J2000 aberration constant (20.49552 arcsec).
This is a reflection of the fact that the E-terms embodied in
existing star catalogues were computed from a variety of
aberration constants. Rather than adopting one of the old
constants the latest value is used here.
References:
1 Smith, C.A. et al., 1989. Astr.J. 97, 265.
2 Yallop, B.D. et al., 1989. Astr.J. 97, 274.
P.T.Wallace Starlink 23 August 1996
Copyright (C) 1996 Rutherford Appleton Laboratory
Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
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