Context. With the increasing knowledge of the terrestrialplanets due to recent space probes it is possible to model theirrotation with increasing accuracy. Despite that fact, an accuratedetermination of Venus precession and nutation is lacking Aims. Although Venus rotation has been studied in severalaspects, a full and precise analytical model of its precession-nutationmotion remains to be constructed. We propose to determine this motionwith up-to-date physical parameters of the planet Methods. We adopt a theoritical framework already used for aprecise precession-nutation model of the Earth, based on a Hamiltonianformulation, canonical equations and an accurate development of theperturbing function due to the Sun. Results. After integrating the disturbing function and applying the canonical equations, we can evaluate the precession constant and the coefficients of nutation, both in longitude and in obliquity. We get ,corresponding to a precession period of years.This result, based on recent estimations of the Venus moment of inertiais significantly different from previous estimations. The largestnutation coefficient in longitude with an argument 2 LS (whereLSis the longitude of the Sun) has a 2''19 amplitude and a 112.35dperiod. We show that the coefficients of nutation of Venus due to itstriaxiality are of the same order of amplitude as these values due toits dynamical flattening, unlike of the Earth, for which they arenegligible. Conclusions. We have constucted a complete theory of therotation of a rigid body applied to Venus, with up-to-datedeterminations of its physical and rotational parameters. This allowedus to set up a new and better constrained value of the Venus precessionconstant and to calculate its nutation coefficients for the first time.Key words: astrometry - celestial mechanics - planets and satellites: individual: Venus
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