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Barium (Ba) dwarfs and CH subgiants are the less-evolved analogues of Ba andCH giants. They are F- to G-type main-sequence stars polluted with heavyelements by a binary companion when the latter was on the Asymptotic GiantBranch (AGB). This companion is now a white dwarf that in most cases cannot bedirectly detected. We present a large systematic study of 60 objects classifiedas Ba dwarfs or CH subgiants. Combining radial-velocity measurements fromHERMES and SALT high-resolution spectra with radial-velocity data from CORAVELand CORALIE, we determine the orbital parameters of 27 systems. We also derivetheir masses by comparing their location in the Hertzsprung-Russell diagramwith evolutionary models. We confirm that Ba dwarfs and CH subgiants are not atdifferent evolutionary stages and have similar metallicities, despite theirdifferent names. Additionally, Ba giants appear significantly more massive thantheir main-sequence analogues. This is likely due to observational biasesagainst the detection of hotter main-sequence post-mass-transfer objects.Combining our spectroscopic orbits with the Hipparcos astrometric data, wederive the orbital inclinations and the mass of the WD companion for foursystems. Since this cannot be done for all systems in our sample yet (butshould be with upcoming Gaia data releases), we also analyse the mass-functiondistribution of our binaries. We can model this distribution with very narrowmass distributions for the two components and random orbital orientation on thesky. Finally, based on BINSTAR evolutionary models, we suggest that the orbitalevolution of low-mass Ba systems can be affected by a second phase ofinteraction along the Red Giant Branch of the Ba star, impacting on theeccentricities and periods of the giants.

Barium & related stars and their white-dwarf companions II. Main-sequence and subgiant stars