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Proportionality of orbital periods for two celestial bodies
Commensurability is the property of two
orbiting objects, such as
planets ,
satellites , or
asteroids , whose
orbital periods are in a
rational
proportion .
Examples include the 2:3 commensurability between the orbital periods of
Neptune and
Pluto ,
[1] the 3:4 commensurability between the orbital periods of the
Saturnian satellites
Titan and
Hyperion ,
[2] the orbital periods associated with the
Kirkwood gaps in the
asteroid belt relative to that of
Jupiter ,
[3] and the 2:1 commensurability between
Gliese 876 b and
Gliese 876 c .
Commensurabilities are normally the result of an
orbital resonance , rather than being due to coincidence.
See also
References
^ Williams, J. G.; Benson, G. S. (March 1971), "Resonances in the Neptune-Pluto System", Astronomical Journal , 76 : 167,
Bibcode :
1971AJ.....76..167W ,
doi :
10.1086/111100 ,
S2CID
120122522 .
^ Bevilacqua, R.; et al. (April 1980), "Resonances and close approaches. I - The Titan-Hyperion case", Laboratorio di Astrofisica Spaziale di Frascati, European Workshop on Planetary Sciences, Rome, Italy, Apr. 23-27, 1979 , vol. 22, p. 141,
Bibcode :
1980M&P....22..141B ,
doi :
10.1007/BF00898423 ,
S2CID
119442634 .
^ Moons, Michèle (March 1996), "Review of the dynamics in the Kirkwood gaps", Celestial Mechanics and Dynamical Astronomy , 65 (1−2): 175−204,
Bibcode :
1996CeMDA..65..175M ,
doi :
10.1007/BF00048446 ,
S2CID
121242252 .