J/A+A/701/A64ivo://CDS.VizieR/J/A+A/701/A64doi:10.26093/cds/vizier/bc-nx/lgeCDSEmsenhuber A.Mordasini C.Mayor M.Marmier M.Udry S.Burn R.,Schlecker M.Mishra L.Alibert Y.Benz W.Asphaug E.2026-08-03T06:57:34Z2025-09-03T07:35:59ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsorbitsmetallicityvisible-astronomyPlanetary population synthesis is a tool that is used to better understand the key processes of planet formation at the statistical level. We seek to quantify the fidelity with which modern population syntheses reproduce observations in view of their use as predictive tools. We compared synthetic populations from the Generation 3 Bern Model of Planet Formation and Evolution (core accretion, solar-type host stars) and the HARPS/Coralie radial velocity sample. We biased the synthetic planet population according to the completeness of the observed data. We then performed quantitative statistical comparisons and systematically identified agreements and differences. Our nominal population reproduces many of the main features of the HARPS planets, such as two main groups of planets in the mass-distance diagram (close-in sub-Neptunes and distant giants), a bimodal mass function with a less populated "desert", an observed mean multiplicity of about 1.6, and several key correlations regarding the stellar metallicity dependency, the period ratio distribution, and the eccentricity distribution. Considering that the model was not optimised beforehand to reproduce any particular survey, this indicates that some of the important physical processes governing planetary formation could be captured. The remaining discrepancies that can be quantified thanks to the population synthesis approach point to areas that are not fully captured in the model. For instance, we find that the synthetic population has (1) in absolute terms too many planets by ~70%, (2) a "desert" that is too deep by ~60%, (3) a relative excess of giant planets by ~40%, (4) planet eccentricities that are on average too low by a factor of about two (median of 0.07 versus 0.15), and (5) a metallicity effect that is too weak. Finally, the synthetic planets are overall too close to the star compared to the HARPS sample. The differences allowed us to find model parameters that better reproduce the observed planet masses, for which we computed additional synthetic populations. We find that decreasing the planet formation efficiency by increasing the planetesimal size re-balances the number of sub-Neptunes versus giant planets. Changing the efficiency of gas-driven migration also affects the sub-Neptune to giant planet ratio, with lower migration rates resulting in more giant planets and fewer sub-Neptunes. However, only modifying the model parameters seems to be insufficient for the model to fully reproduce both the observed mass and distance distributions at the same time. Instead, physical processes appear to be missing. Planets may originate on wider orbits than our model predicts. Mechanisms leading to higher eccentricities and slower disc-limited gas accretion also seem necessary. We also advocate that theoretical models should make a quantitative, rather than merely a qualitative, comparison between the many current and future large surveys and theoretical results to better understand the origins of planetary systems.2025A&A...701A..64Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/701/A64CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/701/A64https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/701/A64http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/701/A64https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/701/A64https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/701/A64http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/701/A64GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/701/A64/tablec1 (List of planets from the HARPS/Coralie surveys)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/701/A64/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/701/A64/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/701/A64/tablec1?GETtext/xml+votable180.050000true1.5798972-49.07518640.0055555555555555566/16652 16995 17266 17341 17496 17641 17730 18614 18641 18747 18821 20557 20593 20746 21121 21484 22036 22590 22654 23201 24831 24924 25140 25466 26183 27018 28763 29289 29291 29513 29541 30943 32848 32986 33091 33430 33456 33510 33608 33630 33705 33813 34390 34446 34905 35362 35442 35532 35954 35968 37573 37954-37955 38238 38311 38414 38461 38545 38728 38742 38807 38975 39257 39364 39646 40143 40220 40442 40692 40985 41058 41204 41432 41607 41724 41752 41912 41941 42248 42845 43012 43228 43813 43818 43911 44243 44398 45258 45364 45668 45717 45865 46112 46287 46297 46306 46800 46967 47550 47780 48105 48519 48530 48652https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/701/A64?format=asciiOpticaldefaultJ/A+A/701/A64/tablec1List of planets from the HARPS/Coralie surveysrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamePlanet namemeta.id;meta.maincharPeriod? Orbital perioddtime.perioddoublenullableEcc? Orbital eccentricitysrc.orbital.eccentricityfloatnullableMsini? Minimum mass(5.97236x10+24kg)phys.massfloatnullablePeriodl? Orbital period according to the litteraturedtime.periodfloatnullablen_Periodl[*] Significant difference in period (1)meta.notecharl_EcclUpper limit flag on Ecclmeta.code.errorcharEccl? Orbital eccentricity according to the litteraturesrc.orbital.eccentricityfloatnullablen_Eccl[*] Significant difference in orbital eccentricity (1)meta.notecharMsinil? Minimum mass according to the litterature(5.97236x10+24kg)phys.massfloatnullablen_Msinil[*] Significant difference in mass (1)meta.notechar[Fe/H]Stellar metallicityphys.abund.ZfloatRefdiscReference for the discovery (BibCode)meta.bib.bibcodecharRefmetaReference for the metallicity value (BibCode)meta.bib.bibcodecharReflittReference for the litterature values (BiBcode)meta.bib.bibcodecharSimbadNameSimbad column added by the CDSmeta.idcharnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main