Nutation In Ecliptical Longitude (ΔΨ) and Right Ascension (ΔRA) Date:     ±Y  m  d Time:   H M S       UT ±ΔT:      H M S Calendar Mode: Julian   Gregorian
 NUTATION IN ECLIPTICAL LONGITUDE AND IN RA (1980 IAU THEORY) DATE ±y m d = 2020 Dec 01 = Tuesday (Gregorian) TIME hh:mm:ss = 00:00:00.000 UT Delta T ± hh:mm:ss = +00:00:00.000 Time of Day Frac = +0 Delta T Day Frac = +0 JD = 2459184.5 JD00 = 2459184.5 JD12 = 2459185 T = 0.2091581108 = Julian centuries reckoned from J2000.0 -------------------------------- Nutation In Ecliptical Longitude Delta psi = -18.027" = +-0.0050076174° ------------------------------------------ Nutation In RA (Equation of the Equinoxes) Delta RA = -01.1027s = -16.540" = -0.0045944833° Algorithm To Compute The Nutation In Longitude (dPsi) The following algorithm computes the nutation in ecliptical longitude, in degrees, for a given JD argument.   It is is based on the 1980 IAU Theory of Nutation and Reduction. This value is the correction to apply to the MEAN value of the ecliptical longitude to obtain the TRUE longitude, with a theoretical precision of ±0.001 arc sec. Any trigonometric functions (sin, cos, tan, et al.) used in the pseudo-code, assume radian arguments unless otherwise indicated.   In this case, the final result is being converted into degrees for convenience. Ref: Astronomical Algorithms - 2nd Edition (1998) Jean Meeus Pub. Willmann-Bell, Inc. ISBN 0-943396-61-1 Ref: Explanatory Supplement to the Astronomical Almanac (1992) p111 to p114 ISBN 0-935702-68-7 WikiRef: http://en.wikipedia.org/wiki/Nutation