Astron. Astrophys. 318, 639-652 (1997)

7. Conclusion

In the present paper we have studied small contributions to the nutation for a rigid Earth model. One part concerns the influence of the coeffficients of the geopotential others than . The other part is the direct action of the planets on the nutation. Our calculations are refined with respect to previous ones done by Kinoshita & Souchay (1990) mainly because of the change of the level of truncation of the series (0.5 µas instead of 5 µas), but also because we keep all the terms in the Fourier series of intermediate calculations with a relative absolute value instead of in (Kinoshita & Souchay 1990). A few errors found in this last paper are corrected.

Table 1 gives all the coefficients of nutation due to , and Table 2 those due to the triaxiality of the Earth, whereas Tables 3 to 6 show the coefficients due to the direct influence of the planets. Moreover in end of Sect. 3, we have shown the three biggest components, both in and , coming from the influence.

Comparisons of our results with those for the coefficients of the nutation due to the and geopotential as calculated by Hartmann et al. (1995) and with those due to the direct action of the planets calculated by Williams (1995) show a quasi-perfect agreement, although the way of calculation is quite different.

© European Southern Observatory (ESO) 1997

Online publication: July 8, 1998
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