ee00b¶
- erfa.ee00b(date1, date2)[source]¶
Equation of the equinoxes, compatible with IAU 2000 resolutions but using the truncated nutation model IAU 2000B.
- Parameters:
- date1double array
- date2double array
- Returns:
- c_retvaldouble array
Notes
Wraps ERFA function
eraEe00b
. The ERFA documentation is:- - - - - - - - - e r a E e 0 0 b - - - - - - - - - Equation of the equinoxes, compatible with IAU 2000 resolutions but using the truncated nutation model IAU 2000B. Given: date1,date2 double TT as a 2-part Julian Date (Note 1) Returned (function value): double equation of the equinoxes (Note 2) 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 result, which is in radians, operates in the following sense: Greenwich apparent ST = GMST + equation of the equinoxes 3) The result is compatible with the IAU 2000 resolutions except that accuracy has been compromised (1 mas) for the sake of speed. For further details, see McCarthy & Luzum (2003), IERS Conventions 2003 and Capitaine et al. (2003). Called: eraPr00 IAU 2000 precession adjustments eraObl80 mean obliquity, IAU 1980 eraNut00b nutation, IAU 2000B eraEe00 equation of the equinoxes, IAU 2000 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. & Luzum, B.J., "An abridged model of the precession-nutation of the celestial pole", Celestial Mechanics & Dynamical Astronomy, 85, 37-49 (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.