J/AJ/162/55ivo://CDS.VizieR/J/AJ/162/55doi:10.26093/cds/vizier.51620055CDSYee S.W.Tamayo D.Hadden S.Winn J.N.2022-03-16T12:18:00Z2021-11-30T07:29:14ZCDS support team

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

cds-question@unistra.frexoplanetsvariable-starsstellar-massesTransit surveys have revealed a significant population of compact multiplanet systems, containing several sub-Neptune-mass planets on close-in, tightly-packed orbits. These systems are thought to have formed through a final phase of giant impacts, which would tend to leave systems close to the edge of stability. Here, we assess this hypothesis, comparing observed eccentricities in systems exhibiting transit-timing variations versus the maximum eccentricities compatible with long-term stability. We use the machine-learning classifier SPOCK (Tamayo et al.) to rapidly classify the stability of numerous initial configurations and hence determine these stability limits. While previous studies have argued that multiplanet systems are often maximally packed, in the sense that they could not host any additional planets, we find that the existing planets in these systems have measured eccentricities below the limits allowed by stability by a factor of 2-10. We compare these results against predictions from the giant-impact theory of planet formation, derived from both N-body integrations and theoretical expectations that, in the absence of dissipation, the orbits of such planets should be distributed uniformly throughout the phase space volume allowed by stability. We find that the observed systems have systematically lower eccentricities than this scenario predicts, with a median eccentricity about four times lower than predicted. This suggests that, if these systems formed through giant impacts, then some dissipation must occur to damp their eccentricities. This may occur through interactions with the natal gas disk or a leftover population of planetesimals, or over longer timescales through the coupling of tidal and secular processes.2021AJ....162...55Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/55CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/217/16 : Kepler planetary candidates. V. 3yr Q1-Q12 (Rowe+, 2015)J/MNRAS/448/1044 : Simul. data for 50 planetary model systems (Hansen+, 2015)J/ApJ/821/47 : KOI transit proba. of multi-planet syst. (Brakensiek+, 2016)J/A+A/605/A72 : Planetary systems AMD-stability (Laskar+, 2017)J/AJ/154/5 : Transit timing variations of 145 Kepler planets (Hadden+, 2017)J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+, 2018)J/AJ/159/281 : Characteristics of 335 KOI stars (Gilbert+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/55https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/162/55/table1 (*Transit-timing variation (TTV) planet properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/162/55/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/162/55/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/162/55/table1?GETtext/xml+votable180.050000true297.11509541.90913970.0055555555555555566/14586 14591 14733 14735 14751 14757 14925 14929 14931 14935 14973 15115-15116 15120 15127 15137 15160 15170 15172https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/162/55?format=asciidefaultJ/AJ/162/55/table1*Transit-timing variation (TTV) planet propertiesIDPlanet identifiermeta.id;meta.maincharPer[3.6/131] Orbital perioddtime.periodfloatMass*[0.5/1.2] Stellar masssolMassphys.massfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE_Mass*[0.03/0.1] Upper uncertainty in M*solMassstat.error;stat.maxfloate_Mass*[0.03/0.1] Lower uncertainty in M*solMassstat.error;phys.massfloatf_Massp[0/1]Limit flag on Mp (1)meta.codeintMassp[0.01/35.2] Planetary mass(5.97236x10+24kg)phys.massfloatE_Massp[0.01/6.7]? Upper uncertainty in Mp(5.97236x10+24kg)stat.error;stat.maxfloatnullablee_Massp[0.01/3.8]? Lower uncertainty in Mp(5.97236x10+24kg)stat.errorfloatnullableZ[0.001/0.16]? Free eccentricity (2)src.orbital.eccentricityfloatnullableE_Z[0/0.1]? Upper uncertainty in Zstat.error;stat.maxfloatnullablee_Z[0/0.1]? Lower uncertainty in Zstat.error;src.redshiftfloatnullableZcom[0.002/0.13]? Center-of-mass eccentricity (3)src.orbital.eccentricityfloatnullableE_Zcom[0.004/0.08]? Upper uncertainty in Zcomstat.error;stat.maxfloatnullablee_Zcom[0.002/0.05]? Lower uncertainty in Zcomstat.errorfloatnullableZ/Zuns[0.09/09]? Fractional distance to instability of systempos.distance;src.redshift;arith.ratiofloatnullableE_Z/Zuns[0.06/0.3]? Upper uncertainty in Z/Zunsstat.error;stat.maxfloatnullablee_Z/Zuns[0/0.2]? Lower uncertainty in Z/Zunsstat.error;src.redshiftfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.main