File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: On the orbits and masses of the satellites of the Pluto-Charon system

TitleOn the orbits and masses of the satellites of the Pluto-Charon system
Authors
KeywordsCelestial Mechanics
Charon
Dynamics
Orbital
Pluto
Resonances
Satellites
Satellites
Issue Date2006
PublisherAcademic Press. The Journal's web site is located at http://www.elsevier.com/locate/icarus
Citation
Icarus, 2006, v. 184 n. 2, p. 573-583 How to Cite?
AbstractTwo small satellites of Pluto, S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), have recently been discovered outside the orbit of Charon, and their orbits are nearly circular and nearly coplanar with that of Charon. Because the mass ratio of Charon-Pluto is ∼0.1, the orbits of P2 and P1 are significantly non-Keplerian even if P2 and P1 have negligible masses. We present an analytic theory, with P2 and P1 treated as test particles, which shows that the motion can be represented by the superposition of the circular motion of a guiding center, the forced oscillations due to the non-axisymmetric components of the potential rotating at the mean motion of Pluto-Charon, the epicyclic motion, and the vertical motion. The analytic theory shows that the azimuthal periods of P2 and P1 are shorter than the Keplerian orbital periods, and this deviation from Kepler's third law is already detected in the unperturbed Keplerian fit of Buie and coworkers. In this analytic theory, the periapse and ascending node of each of the small satellites precess at nearly equal rates in opposite directions. From direct numerical orbit integrations, we show the increasing influence of the proximity of P2 and P1 to the 3:2 mean-motion commensurability on their orbital motion as their masses increase within the ranges allowed by the albedo uncertainties. If the geometric albedos of P2 and P1 are high and of order of that of Charon, the masses of P2 and P1 are sufficiently low that their orbits are well described by the analytic theory. The variation in the orbital radius of P2 due to the forced oscillations is comparable in magnitude to that due to the best-fit Keplerian eccentricity, and there is at present no evidence that P2 has any significant epicyclic eccentricity. However, the orbit of P1 has a significant epicyclic eccentricity, and the prograde precession of its longitude of periapse with a period of 5300 days should be easily detectable. If the albedos of P2 and P1 are as low as that of comets, the large inferred masses induce significant short-term variations in the epicyclic eccentricities and/or periapse longitudes on the 400-500-day timescales due to the proximity to the 3:2 commensurability. In fact, for the maximum inferred masses, P2 and P1 may be in the 3:2 mean-motion resonance, with the resonance variable involving the periapse longitude of P1 librating. Observations that sample the orbits of P2 and P1 well on the 400-500-day timescales should provide strong constraints on the masses of P2 and P1 in the near future. © 2006 Elsevier Inc. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/151194
ISSN
2015 Impact Factor: 3.383
2015 SCImago Journal Rankings: 2.447
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorLee, MHen_US
dc.contributor.authorPeale, SJen_US
dc.date.accessioned2012-06-26T06:18:29Z-
dc.date.available2012-06-26T06:18:29Z-
dc.date.issued2006en_US
dc.identifier.citationIcarus, 2006, v. 184 n. 2, p. 573-583en_US
dc.identifier.issn0019-1035en_US
dc.identifier.urihttp://hdl.handle.net/10722/151194-
dc.description.abstractTwo small satellites of Pluto, S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), have recently been discovered outside the orbit of Charon, and their orbits are nearly circular and nearly coplanar with that of Charon. Because the mass ratio of Charon-Pluto is ∼0.1, the orbits of P2 and P1 are significantly non-Keplerian even if P2 and P1 have negligible masses. We present an analytic theory, with P2 and P1 treated as test particles, which shows that the motion can be represented by the superposition of the circular motion of a guiding center, the forced oscillations due to the non-axisymmetric components of the potential rotating at the mean motion of Pluto-Charon, the epicyclic motion, and the vertical motion. The analytic theory shows that the azimuthal periods of P2 and P1 are shorter than the Keplerian orbital periods, and this deviation from Kepler's third law is already detected in the unperturbed Keplerian fit of Buie and coworkers. In this analytic theory, the periapse and ascending node of each of the small satellites precess at nearly equal rates in opposite directions. From direct numerical orbit integrations, we show the increasing influence of the proximity of P2 and P1 to the 3:2 mean-motion commensurability on their orbital motion as their masses increase within the ranges allowed by the albedo uncertainties. If the geometric albedos of P2 and P1 are high and of order of that of Charon, the masses of P2 and P1 are sufficiently low that their orbits are well described by the analytic theory. The variation in the orbital radius of P2 due to the forced oscillations is comparable in magnitude to that due to the best-fit Keplerian eccentricity, and there is at present no evidence that P2 has any significant epicyclic eccentricity. However, the orbit of P1 has a significant epicyclic eccentricity, and the prograde precession of its longitude of periapse with a period of 5300 days should be easily detectable. If the albedos of P2 and P1 are as low as that of comets, the large inferred masses induce significant short-term variations in the epicyclic eccentricities and/or periapse longitudes on the 400-500-day timescales due to the proximity to the 3:2 commensurability. In fact, for the maximum inferred masses, P2 and P1 may be in the 3:2 mean-motion resonance, with the resonance variable involving the periapse longitude of P1 librating. Observations that sample the orbits of P2 and P1 well on the 400-500-day timescales should provide strong constraints on the masses of P2 and P1 in the near future. © 2006 Elsevier Inc. All rights reserved.en_US
dc.languageengen_US
dc.publisherAcademic Press. The Journal's web site is located at http://www.elsevier.com/locate/icarusen_US
dc.relation.ispartofIcarusen_US
dc.subjectCelestial Mechanicsen_US
dc.subjectCharonen_US
dc.subjectDynamicsen_US
dc.subjectOrbitalen_US
dc.subjectPlutoen_US
dc.subjectResonancesen_US
dc.subjectSatellitesen_US
dc.subjectSatellitesen_US
dc.titleOn the orbits and masses of the satellites of the Pluto-Charon systemen_US
dc.typeArticleen_US
dc.identifier.emailLee, MH:mhlee@hku.hken_US
dc.identifier.authorityLee, MH=rp00724en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/j.icarus.2006.04.017en_US
dc.identifier.scopuseid_2-s2.0-33748883268en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-33748883268&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume184en_US
dc.identifier.issue2en_US
dc.identifier.spage573en_US
dc.identifier.epage583en_US
dc.identifier.isiWOS:000241007200022-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLee, MH=7409119699en_US
dc.identifier.scopusauthoridPeale, SJ=6602697819en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats