Budding, E.Butland, R.2025-01-272025-01-2720110035-8711https://doi.org/10.1111/j.1365-2966.2011.19597.xhttps://hdl.handle.net/20.500.12428/21834New high-resolution spectroscopy of the Algol-type binary R CMa is presented and reduced, allowing a re-analysis of this puzzling close pair. New radial velocity curves are in better agreement with the results of Glazunova, Yushchenko & Mrktichian, which revise upwards the relatively low masses of Tomkin. We find the following main parameters: M1= 1.67 +/- 0.08, M2= 0.22 +/- 0.07; R1= 1.78 +/- 0.03, R2= 1.22 +/- 0.07; L1= 8.2 +/- 0.2, L2= 0.49 +/- 0.01 (solar units); and photometric parallax 22 +/- 1 mas. Certain anomalous features of the system remain, however, in particular the combination of low period P and low mass ratio q. This may be related to the third body known to attend the close eclipsing pair, for which we also provide a new astrometric analysis and accompanying numerical results: M(3) = 0.8 +/- 0.1; R(3) = 0.83 +/- 0.07; L(3) = 0.4 +/- 0.1 ( solar units). The ` R CMa type', within the context of Algol evolution, may be seen as involving an unusually low q, P combination.eninfo:eu-repo/semantics/closedAccessmethods: data analysisbinaries: closestars: individual: R CMaGalaxy: stellar contentArticle41831764177310.1111/j.1365-2966.2011.19597.xQ1WOS:000298088000024