J/AJ/154/62ivo://CDS.VizieR/J/AJ/154/62doi:10.26093/cds/vizier.51540062CDSVolk K.Malhotra R.2018-03-12T09:20:49Z2017-11-07T14:29:30ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsolar-systemasteroidsWe measured the mean plane of the Kuiper Belt as a function of semimajor axis. For the classical Kuiper Belt as a whole (the nonresonant objects in the semimajor axis range 42-48au), we find a mean plane of inclination i_m_=1.8{deg}_-0.4{deg}_^+0.7{deg}^ and longitude of ascending node {Omega}_m_=77{deg}_-14{deg}_^+18{deg}^ (in the J2000 ecliptic-equinox coordinate system), in accord with theoretical expectations of the secular effects of the known planets. With finer semimajor axis bins, we detect a statistically significant warp in the mean plane near semimajor axes 40-42au. Linear secular theory predicts a warp near this location due to the {nu}_18_ nodal secular resonance; however, the measured mean plane for the 40.3-42au semimajor axis bin (just outside the {nu}_18_) is inclined ~13{deg} to the predicted plane, a nearly 3{sigma} discrepancy. For the more distant Kuiper Belt objects of semimajor axes in the range 50-80au, the expected mean plane is close to the invariable plane of the solar system, but the measured mean plane deviates greatly from this: it has inclination i_m_=9.1{deg}_-3.8{deg}_^+6.6{deg}^ and longitude of ascending node {Omega}_m_=227{deg}_-44{deg}_^+18{deg}^. We estimate this deviation from the expected mean plane to be statistically significant at the ~97%-99% confidence level. We discuss several possible explanations for this deviation, including the possibility that a relatively close-in (a<~100au), unseen, small planetary-mass object in the outer solar system is responsible for the warping.2017AJ....154...62Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/62CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/astorb : Orbits of Minor Planets (Bowell+ 2014)http://www.minorplanetcenter.net/ : Minor Planet Centerhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/62https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/62http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/62https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/62https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/62http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/62GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/154/62/table1List objects used to calculate mean planesNamemeta.id;meta.mainchare[0.0018/0.76] Best-fit eccentricity (2)src.orbital.eccentricitydoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMPCMinor Planet Center designation (1)meta.idchara[36.3/149.85] Best-fit barycentric semi-major axis (2)AUpos.distance;phys.size;meta.modelleddoublee_a[0.0005/4.14] The 1-{sigma} uncertainty in a (da) (3)AUstat.errordoublei[0.0018/0.88] Best-fit inclination (2)radsrc.orbital.inclination;meta.modelleddoubleOmega[0.0022/6.28] Best-fit longitude of ascending node ({Omega}) (2)radsrc.orbital.nodedoubleomega[0.0014/6.27] Best-fit argument of perihelion ({omega}) (2)radsrc.orbital.periastron;meta.modelleddoublelambda[-3.14/3.14] Ecliptic longitude ({lambda}) (2)radpos.ecliptic.lonfloatbeta[-0.844/0.805] Ecliptic latitude ({beta}) (2)radpos.ecliptic.latfloatDist[31.544/96.255] Heliocentric distance (r_h_)AUpos.distance;pos.heliocentricfloatEpochEpoch of the orbit fit and sky position (in Julian Date)dtime.epochdouble