J/A+A/630/A135ivo://CDS.VizieR/J/A+A/630/A135doi:10.26093/cds/vizier.36300135CDSUlmer-Moll S.Santos N.C.Figueira P.Brinchmann J.Faria J.P.2020-12-01T16:12:20Z2019-10-09T08:08:41ZCDS support team

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

cds-question@unistra.frexoplanetsgalaxy-classification-systemsstellar-massesstellar-radiiThe mass and radius are two fundamental properties to characterize exoplanets but only for a relatively small fraction of exoplanets are they both available. The mass is often derived from radial velocity measurements while the radius is almost always measured with the transit method. For a large number of exoplanets, either the radius or the mass is unknown, while the host star has been characterized. Several mass-radius relations dependent on the planet's type have been published which often allow to predict the radius, as well as a bayesian code which forecasts the radius of an exoplanet given the mass or vice versa. Our goal is to derive the radius of exoplanets using only observables extracted from spectra used primarily to determine radial velocities and spectral parameters. Our objective is to obtain a mass-radius relation that is independent of the planet's type. We work with a database of confirmed exoplanets with known radii and masses as well as the planets from our Solar System. Using random forests, a machine learning algorithm, we compute the radius of exoplanets and compare the results to the published radii. Our code, BEM, is available online. On top of this, we also explore how the radius estimates compare to previously published mass-radius relations. The estimated radii reproduces the spread in radius found for high mass planets better than previous mass-radius relations. The average error on the radius is 1.8R_Earth_ across the whole range of radii from 1 to 22R_Earth_. We found that a random forest algorithm is able to derive reliable radii especially for planets between 4 and 20R_Earth_, for which the error is smaller than 25%. The algorithm has a low bias but still a high variance, which could be reduced by limiting the growth of the forest or adding more data. The random forest algorithm is a promising method to derive exoplanet properties. We show that the exoplanet's mass and equilibrium temperature are the relevant properties which constrain the radius, and do it with higher accuracy than the previous methods.2019A&A...630A.135Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/630/A135CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-towww.exoplanet.eu : The Extrasolar Planets Encyclopaedia Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/630/A135https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/630/A135http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/630/A135https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/630/A135https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/630/A135http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/630/A135GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/630/A135/training (Parameters of planets in training set)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/630/A135/training?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/630/A135/training?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/630/A135/training?GETtext/xml+votable180.050000true245.151541.04808330.005555555555555556Cone search capability for table J/A+A/630/A135/testing (Parameters of planets in testing set)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/630/A135/testing?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/630/A135/testing?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/630/A135/testing?GETtext/xml+votable180.050000true118.063416712.13938890.0055555555555555566/413 437 679 790 876 913 935 960 1275 2250 2297 2308 2335 2532 2551 2577 2584 2596 2711 3344 3876 3979 4145 4272 4280 4429 4521 4624 4651 4659 4730 4866 5009 5170 5475 5730 6017 6058 6181 6349 6381 6539 6638 6760 7036 7208 7240 7447 7502 7649 7917 8197 8237 8825 8843 8992 9173 9459 9482 9524 9653 9811 10079 10118 10407 10654 10701 10730 10953 11279 11455 12342 12398 12424 12486 12612 12644 12853 12862 12983 13044 13143 13423 13439 13569 13680 13688 13702 14278 14555 14567 14573 14579 14581 14591 14735 14746 14757 14762-14764 14768 14772 14777 14779-14780 14816 14824-14826 14886 14918 14920 14924 14929 14936 14939-14940 14942 14945 14952 14961 14963 14973 14993 15029 15040 15060 15105 15110 15112 15121-15122 15126 15129 15131 15143 15149 15153-15154 15159-15160 15162 15174 15218 15950 16074 16405 16432 16512 16534 16633 16768 16847 16947 17040 17162 17172 17202 17226-17227 17430 17819 17851 17865 18093 18147 18163 18223 18350 18452-18453 18539 18569 18696 18726 18766 18785 18800 18880 18943 19160 19371 19669 20116 20145 20455 20476 20501 20543 20565 20648 20659 20682 20741 20780 20790 20872 21003 21026 21176 21223 21406 21461 21876 21989 22001 22034 22040 22065 22078-22079 22120 22168-22169 22208 22252 22396 22505 22963 24039 24057 24122 24205 24409 24428 24622 24752 24815 24858 24981 25132 25140 25153 25194 25283 25427 25433 25454 25463 25604 25673 25699 25721 25725 25794 25885 25950 26062 26278 26706 26727 26771 26918 26977 26990 26992 27056 27164 27324 27488 27548 27787 28400 28548 28822 29012 29022 29045 29349 29683 30009 30013 30157 30170 30240-30241 30293 30295 30344 30436 30439 30444 30447 30450-30451 30456 30466 31216 31641 31813 31858 32217 32564 32640 32659 32727 32749 33145 33157 33200 33210 33220 33283 33386 33449 33719 33723 33798 33972 34260 34370 34526 34566 34708 34751 34812 34847-34848 34860 34898 34940 34957 35210 35456 36092 36142 36165 36196-36197 36497 36667 37246-37247 37274 37329 37393 37461 37923 38233 38246 38452 38464 38545 38644 38682 39257 39474 39512 39542 39611 39667 39733 39812 39826 39829 39851 40014 40022 40194 40251 40320 40862 42001 42318 42865 42936 43180 43233 43247-43248 43257 43336 43432 43541 43586 43639 43656 43775 43847 43865 43960 44200 44335 44436 44471 44648 44672 44685 45041 45380 45527 45766 45800 45855 45890 45922 46058 46121 46135 46316 46421 46429 46437 46771 46873 47000 47154 47167 47186 47307 47330 47456 47476 48005 48076 48082 48105 48108-48109 48111 48114 48117 48165 48178 48251 48327 48338 48353 48364 48415 48501 48674 48727 48729 48803 48945 49103https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/630/A135?format=asciiOpticaldefaultJ/A+A/630/A135/trainingParameters of planets in training setSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the planetmeta.id;meta.maincharMassPlanetary mass (1)(5.97236x10+24kg)phys.massdoubleRadiusPlanetary radius (1)(6.3781x10+6m)phys.size.radiusdoubleamajSemi major axis (1)AUphys.size.smajAxisdoubleTeqPlanet equilibrium temperatureKphys.temperaturedoubleL*Stellar luminositysolLumphys.luminositydoubleM*Stellar mass (1)solMassphys.massdoubleR*Stellar radius (1)solRadphys.size.radiusdoubleTeff*Stellar effective temperature (1)Kphys.temperature.effectiveint_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullableJ/A+A/630/A135/testingParameters of planets in testing setSimbadNameSimbad column added by the CDSmeta.idcharNameName of the planetmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMassPlanetary mass (1)(5.97236x10+24kg)phys.massdoubleRadiusPlanetary radius (1)(6.3781x10+6m)phys.size.radiusdoubleamajSemi major axis (1)AUphys.size.smajAxisdoubleTeqPlanet equilibrium temperatureKphys.temperaturedoubleL*Stellar luminositysolLumphys.luminositydoubleM*Stellar mass (1)solMassphys.massdoubleR*Stellar radius (1)solRadphys.size.radiusdoubleTeff*Stellar effective temperature (1)Kphys.temperature.effectiveint_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullable