EDP Sciences
Free access
Volume 389, Number 3, July III 2002
Page(s) 1047 - 1054
Section Celestial mechanics and astrometry
DOI http://dx.doi.org/10.1051/0004-6361:20020734

A&A 389, 1047-1054 (2002)
DOI: 10.1051/0004-6361:20020734

Indirect effect of the triaxiality in the Hamiltonian theory for the rigid Earth nutations

A. Escapa1, J. Getino2 and J. M. Ferrándiz1

1  Dpto. de Matemática Aplicada, Escuela Politécnica Superior, Universidad de Alicante, 03080 Alicante, Spain
2  Grupo de Mecánica Celeste, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain

(Received 20 September 2001 / Accepted 30 April 2002 )

In this investigation we determine a new contribution to the nutation series due to an indirect effect of the triaxiality of the rigid Earth. We undertake this work in the context of the Hamiltonian theory for the rigid Earth, developed by Kinoshita (1977) and recently updated by Souchay et al. (1999). To do this, we express the potential energy in terms of the action-angle variables for the triaxial Earth. Then, we work out analytical formulae for the new contributions, showing that their numerical values are within the truncation level adopted by REN-2000 (Souchay et al. 1999), which was fixed to $0.1\;\mu$as.

Key words: celestial mechanics

Offprint request: A. Escapa, Alberto.Escapa@ua.es

© ESO 2002