TY - JOUR

T1 - The Relative Motion and Shapes of Pluto and Charon

AU - Kholshevnikov, K. V.

AU - Mikryukov, D. V.

AU - Jazmati, M. S.

N1 - Publisher Copyright: © 2021, Pleiades Publishing, Ltd.

PY - 2021/7

Y1 - 2021/7

N2 - Abstract: The comparative effect of two factors on the translatory motion of the centers of mass of the Pluto–Charon system is investigated. The first important factor is the non-sphericity of the shape and gravitational field of the bodies in the system. The second factor is the gravitation of the Sun. As a measure of the influence of both factors we use the ratio of the corresponding perturbing acceleration to the main one. The main acceleration is caused by the mutual Newtonian attraction of Pluto and Charon. It has been established that for the first factor this measure is on the order of 10–6, while for the second factor it is two orders of magnitude smaller. This explains why the Lidov–Kozai effect (despite a large mutual slope of 96° between the planes of the satellite’s orbit around the planet, and the barycenter of the system around the Sun) does not appear. The situation is similar to the case with the satellites of Uranus. As a result, the Pluto–Charon system remains stable at least on a timescale of millions of years. The tidal effect of the Sun on the surface shape of the bodies under study is also estimated. The ratio of the tidal potential of the Sun at a point on the surface of the body to the gravitational potential of the body itself at this point is taken as a measure of impact. It turned out to be on the order of 3 × 10–12, which is more than six orders less than the influence of rotation and mutual attraction of Pluto and Charon. In fact, the Sun does not affect the figures of the bodies of the system.

AB - Abstract: The comparative effect of two factors on the translatory motion of the centers of mass of the Pluto–Charon system is investigated. The first important factor is the non-sphericity of the shape and gravitational field of the bodies in the system. The second factor is the gravitation of the Sun. As a measure of the influence of both factors we use the ratio of the corresponding perturbing acceleration to the main one. The main acceleration is caused by the mutual Newtonian attraction of Pluto and Charon. It has been established that for the first factor this measure is on the order of 10–6, while for the second factor it is two orders of magnitude smaller. This explains why the Lidov–Kozai effect (despite a large mutual slope of 96° between the planes of the satellite’s orbit around the planet, and the barycenter of the system around the Sun) does not appear. The situation is similar to the case with the satellites of Uranus. As a result, the Pluto–Charon system remains stable at least on a timescale of millions of years. The tidal effect of the Sun on the surface shape of the bodies under study is also estimated. The ratio of the tidal potential of the Sun at a point on the surface of the body to the gravitational potential of the body itself at this point is taken as a measure of impact. It turned out to be on the order of 3 × 10–12, which is more than six orders less than the influence of rotation and mutual attraction of Pluto and Charon. In fact, the Sun does not affect the figures of the bodies of the system.

KW - Kozai effect

KW - planets, satellites, Pluto, Charon, equilibrium figures, Jacobi coordinates, Lidov

KW - satellites

KW - PERTURBATIONS

KW - Jacobi coordinates

KW - Charon

KW - GRAVITY-FIELD

KW - Pluto

KW - Lidov

KW - equilibrium figures

KW - EVOLUTION

KW - planets

KW - ORBITS

KW - INTERIOR STRUCTURE

KW - SATELLITES

UR - http://www.scopus.com/inward/record.url?scp=85113392120&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/ce171155-9416-3533-abc8-3cce11b8135c/

U2 - 10.1134/S1063454121030043

DO - 10.1134/S1063454121030043

M3 - Article

AN - SCOPUS:85113392120

VL - 54

SP - 289

EP - 299

JO - Vestnik St. Petersburg University: Mathematics

JF - Vestnik St. Petersburg University: Mathematics

SN - 1063-4541

IS - 3

ER -