pöörleva ning pretsesseeriva keha pöörlemistelje võnkumine pretsessioonikoonuse suhtes
phenomenon which causes the orientation of the axis of rotation of a spinning astronomical object to vary over time
Hea teada
Astronomical nutation should not be confused with nutation as defined in mechanics; the latter is present even if the source of the torques is unvarying. Reference: Barger, Vernon D., Bolz, Ray E., and Safko, John L. , 'Nutation (astronomy and Mechanics)', AccessScience, McGraw-Hill Education, 2014, https://www.accessscience.com/content/nutation-astronomy-and-mechanics/462400 [8.6.2017]
The nutation happens because of tidal forces that cause the precession of the equinoxes to vary over time so that the speed of the precession is not constant. The largest component of the Earth’s nutation has a period of 18.6 years.
