J/A+A/678/A93ivo://CDS.VizieR/J/A+A/678/A93doi:10.26093/cds/vizier/bc-n6/ljdCDSGratton R.Squicciarini V.Nascimbeni V.Janson M.Reffert S.,Meyer M.Delorme P.Mamajek E.E.Bonavita M.Desidera S.Mesa D.,Rigliaco E.D'Orazi V.Vigan A.Lazzoni C.Chauvin G.Langlois M.2026-07-01T14:01:05Z2023-10-10T10:43:15ZCDS support team

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

cds-question@unistra.frstellar-associationsmultiple-starsb-starsphotometryvisible-astronomyradial-velocitystellar-massesThe frequency, semi-major axis, and mass distribution of stellar companions likely depend on the mass of the primaries and on the environment where the stars form. These properties are very different for early- and late-type stars. However, data are largely incomplete, even for the closest environments to the Sun, preventing a cleaner view of the problem. This paper provides basic information about the properties of companions to B stars in the Scorpius-Centaurus association (age ~15Myr); this is the closest association containing a large population of 181 B-stars. We gathered available data combining high contrast imaging samples from BEAST, SHINE, and previous surveys with evidence of companions from Gaia (both through direct detection and astrometry), from eclipsing binaries, and from spectroscopy. We evaluated the completeness of the binary search and estimated the mass and semi-major axis for all detected companions. These data provide a complete sample of stellar secondaries (extending well in the substellar regime) for separation >3au, and they are highly informative as to closer companions. We found evidence for 200 companions around 181 stars. We did not find evidence for companions for only 43 (23.8+/-3.6%) of the targets, with the fraction being as low as 15.2+/-4.1% for stars with M_A_>3.5M_{sun}_ while it is 31.5+/-5.9% for lower-mass stars. This confirms earlier findings for a clear trend of a binary fraction with stellar mass. The median semi-major axis of the orbits of the companions is smaller for B than in A stars, confirming a turn-over previously found for OB stars. The mass distribution of the very wide (a>1000au) and closer companions is different. Very few companions of massive stars M_A_>5.0M_{sun}_ have a mass below solar and even fewer are M stars with a semi-major axis <1000au. However, the scarcity of low-mass companions extends throughout the whole sample. Period and mass ratio distributions are different for early B stars (up to B7 spectral type) and stars of a later spectral type: most early B stars are in compact systems with massive secondaries, while less massive stars are mainly in wider systems with a larger spread in mass ratios. We derived log-normal fits to the distribution of the semi-major axis and mass ratios for low and high-mass B stars; these relations suggest that it is not probable that the planets and brown dwarf (BD) companions to b Cen and mu2 Sco are extreme cases in the distribution of stellar companions. We interpret our results as the formation of secondaries with a semi-major axis <1000au (about 80% of the total) by fragmentation of the disk of the primary and selective mass accretion on the secondaries. The formation of secondaries within the disk of primaries in close binaries has been proposed by many others before; it unifies the scenarios for formation of close binaries with that of substellar companions that also form within the primary disk, though on a different timescale. We also find that the observed trends with primary mass may be explained by a more prolonged phase of accretion episodes on the disk and by a more effective inward migration. Finally, in the Appendices we describe the detection of twelve new stellar companions from the BEAST survey and of a new BD companion at 9.599 arcsec from HIP 74752 using Gaia data, and we discuss the cases of possible BD and low-mass stellar companions to HIP 59173, HIP 62058, and HIP 64053.2023A&A...678A..93Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A93CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/152/40 : Spectroscopy of 341 bright A- and B-type starsJ/A+A/636/A74 : HARPS radial velocity database (Trifonov+, 2020)J/A+A/657/A7 : Stellar and substellar companions from Gaia EDR3https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A93https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A93http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A93https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A93https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A93http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A93GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/678/A93/tablee1 (Target list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A93/tablee1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A93/tablee1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A93/tablee1?GETtext/xml+votable180.050000true155.7423-66.90150.0055555555555555566/29219 29358 30722 37236 37268 37888 37894 37928 37990 38023 38212 41534 41606-41607 41632 41637 41705 41815 41866 41917 41943 41947 41963 41973 41983 42173 42218 42237 42356 42406-42407 42414 42425 42428 42549 42605 42612 42617-42618 42622-42623 42633 42635 42640 42649 42652 42655-42656 42658 42660 42670 42672 42674 42684 42687 42696 42714 42728 42736 42738 42746 42763 42778 42800 42808 42848 42875 42924 42932 42948 42955 42959 42972 42977-42978 42980 42984-42985 42987 42989-42990 42994 43011 43014 43035 43038 43062 43067 43072 43097 43099 43101 43115 43117 43137-43138 43140 43153 43183 43192 43206 43210-43211 43229-43230 43238 43259 43272 43279 43326 43345 43365 43372 43375 43377-43378 43383 43397 43407 43414 43416 43429 43460 43521 43531 43538 43700 43716 43764 43843 44043-44044 44046 44054 44086 44101 44119 44204 44293 44306-44307 44312-44313 44316-44317 44319 44352 44354 44359-44360 44363 44366 44368 44371 44378 44385 44389 44403 44409 44421 44436 44469 445021.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/678/A93?format=asciiOpticaldefaultJ/A+A/678/A93/tablee1Target listHIPHIP numbermeta.id;meta.mainintSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintONameAlternative designationmeta.idcharHDHD numbermeta.idintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainDistDistance from Gaiapcpos.distancefloatPmemb? Membership probability using Banyanstat.probabilityintnullableSpTypeSpectral type from SIMBADsrc.spTypecharE(B-V)? Reddeningmagphot.color.excessfloatnullableAge? AgeMyrtime.agefloatnullableNoteNotemeta.notecharJ/A+A/678/A93/tablee2Information about binarityrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHIPHIP numbermeta.id;meta.mainintLine[1/3] Line number for this starmeta.idintK2/TESS[T/K2 ] K2 or TESSmeta.codecharRVvarVariable type ftom RV (SB/SB2/EB/RV Var/C)meta.code;src.varchardt? HARPS dt from Trifonov et al. (2020A&A...636A..74T, Cat. J/A+A/636/A74)dtime.intervalfloatnullablesigma? HARPS sigma RV from Trifonov et al. (2020A&A...636A..74T, Cat. J/A+A/636/A74)km/sphys.veloc.dispersionfloatnullableRV? Radial velocity From Gaia DR3km/sphys.veloc;pos.heliocentricfloatnullablee_RV? Radial velocity error From Gaia DR3km/sstat.errorfloatnullablePctRV? Probability of constant RV from Gaia DR3stat.fit.goodnessfloatnullableAmpRV? Amplitude of RV variation from Gaia DR3km/sarith.rate;src.var.amplitudefloatnullableDet[YNx] Detection of secondary by Gullikson et al. (2016AJ....152...40G, Cat. J/AJ/152/40)meta.codecharRUWE? RUWE from Gaia DR3stat.errorfloatnullablePMaSNR? GaiaDR3-Hipparcos proper motion anomaly S/N from Kervella et al. (2022A&A...657A...7K, Cat. J/A+A/657/A7)stat.snrfloatnullableHCIobs? Number of HCI observationsmeta.numberintnullableInt[y] Interferometric observationmeta.codecharSep? Separataion of Gaia cpm companionsarcsecpos.angDistancefloatnullableJ/A+A/678/A93/tablee3PhotometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHIPHIP numbermeta.id;meta.mainintLine[1/4] Line number for this starmeta.idintSep? Companion projected separationarcsecpos.angDistancefloatnullablea? Semi-major axisauphys.angSize;srcdoublenullableGmagAGaia G magnitude of primarymagphot.mag;em.optfloatGmagB? Gaia G magnitude of secondarymagphot.mag;em.optfloatnullableKmagA? 2MASS K magnitude of primarymagphot.mag;em.IR.KfloatnullableKmagB? 2MASS K magnitude of secondarymagphot.mag;em.IR.KfloatnullableGMAGAGaia absolute G mag of primarymagphys.magAbsfloatGMAGB? Gaia absolute G mag of secondarymagphys.magAbsfloatnullableKMAGA? 2MASS K absolute mag of primarymagphot.mag;em.IR.KfloatnullableKMAGB? 2MASS K absolute mag of secondarymagphot.mag;em.IR.KfloatnullableG-K? Corrected G-K colour of primarymagphot.color;em.opt;em.IRfloatnullableMethodBinary detection methodmeta.notecharJ/A+A/678/A93/tablee4Masses of primaries and companionsHIPHIP numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLine[1/4] Line number for this starmeta.idintMassAPrimary masssolMassphys.massfloatMassB? Secondary masssolMassphys.massfloatnullableMassBdyn? Secondary mass (from RUWE or PMa or RV)solMassphys.massfloatnullableq? Mass ratiophys.massfloatnullableNoteSourcemeta.notechar