ee00

erfa.ee00(date1, date2, epsa, dpsi)[source]

The equation of the equinoxes, compatible with IAU 2000 resolutions, given the nutation in longitude and the mean obliquity.

Parameters:
date1double array
date2double array
epsadouble array
dpsidouble array
Returns:
c_retvaldouble array

Notes

Wraps ERFA function eraEe00. The ERFA documentation is:

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 e r a E e 0 0
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The equation of the equinoxes, compatible with IAU 2000 resolutions,
given the nutation in longitude and the mean obliquity.

Given:
   date1,date2  double    TT as a 2-part Julian Date (Note 1)
   epsa         double    mean obliquity (Note 2)
   dpsi         double    nutation in longitude (Note 3)

Returned (function value):
                double    equation of the equinoxes (Note 4)

Notes:

1) The TT date date1+date2 is a Julian Date, apportioned in any
   convenient way between the two arguments.  For example,
   JD(TT)=2450123.7 could be expressed in any of these ways,
   among others:

          date1          date2

       2450123.7           0.0       (JD method)
       2451545.0       -1421.3       (J2000 method)
       2400000.5       50123.2       (MJD method)
       2450123.5           0.2       (date & time method)

   The JD method is the most natural and convenient to use in
   cases where the loss of several decimal digits of resolution
   is acceptable.  The J2000 method is best matched to the way
   the argument is handled internally and will deliver the
   optimum resolution.  The MJD method and the date & time methods
   are both good compromises between resolution and convenience.

2) The obliquity, in radians, is mean of date.

3) The result, which is in radians, operates in the following sense:

      Greenwich apparent ST = GMST + equation of the equinoxes

4) The result is compatible with the IAU 2000 resolutions.  For
   further details, see IERS Conventions 2003 and Capitaine et al.
   (2002).

Called:
   eraEect00    equation of the equinoxes complementary terms

References:

   Capitaine, N., Wallace, P.T. and McCarthy, D.D., "Expressions to
   implement the IAU 2000 definition of UT1", Astronomy &
   Astrophysics, 406, 1135-1149 (2003)

   McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
   IERS Technical Note No. 32, BKG (2004)

This revision:  2021 May 11

Copyright (C) 2013-2023, NumFOCUS Foundation.
Derived, with permission, from the SOFA library.  See notes at end of file.