article published yes J. Bodensteiner author T. Shenar author H. Sana author N. Britavskiy author P. A. Crowther author N. Langer author D. J. Lennon author L. Mahy author L. R. Patrick author J. I. Villaseñor author M. Abdul-Masih author D. M. Bowman author A. De Koter author S. E. De Mink author K. Deshmukh author M. Fabry author A. Gilkis author Ylva Louise Linsdotter Götberg author d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d0000-0002-6960-6911 G. Holgado author R. G. Izzard author S. Janssens author V. M. Kalari author Z. Keszthelyi author J. Kubát author I. Mandel author G. Maravelias author L. M. Oskinova author D. Pauli author V. Ramachandran author D. F. Rocha author M. Renzo author A. A.C. Sander author F. R.N. Schneider author A. Schootemeijer author K. Sen author M. Stoop author S. Toonen author J. T. Van Loon author R. Valli author A. Vigna-Gómez author J. S. Vink author C. Wang author X. T. Xu author YlGo department Context. Rapidly rotating classical OBe stars have been proposed as the products of binary interactions, and the fraction of Be stars with compact companions implies that at least some are. However, to constrain the interaction physics spinning up the OBe stars, a large sample of homogeneously analyzed OBe stars with well-determined binary characteristics and orbital parameters are required. Aims. We investigated the multiplicity properties of a sample of 18 Oe, 62 Be, and two Of?p stars observed within the BLOeM survey in the Small Magellanic Cloud. We analyzed the first nine epochs of spectroscopic observations obtained over approximately three months in 2023. Methods. Radial velocities (RVs) of all stars were measured using cross-correlation based on different sets of absorption and emission lines. Applying commonly used binarity criteria, we classified objects as binaries, binary candidates, and apparently single (RV stable) objects. We further inspected the spectra for double-lined spectroscopic binaries and cross-matched with catalogs of X-ray sources and photometric binaries. Results. We classify 14 OBe stars as binaries, and an additional 11 as binary candidates. The two Of?p stars are apparently single. We find two more objects that are most likely currently interacting binaries. Without those, the observed binary fraction for the remaining OBe sample of 78 stars is fobs+candOBe = 0.18 ± 0.04 (fobs+candOBe = 0.32±0.05 including candidates). This binary fraction is less than half of that measured for OB stars in BLOeM. Combined with the lower fraction of SB2s, this suggests that OBe stars do indeed have fundamentally different present-day binary properties than OB stars. We find no evidence for OBe binaries with massive compact companions, in contrast to expectations from binary population synthesis. Conclusions. Our results support the binary scenario as an important formation channel for OBe stars, as post-interaction binaries may have been disrupted or the stripped companions of OBe stars are harder to detect. Further observations are required to characterize the detected binaries, their orbital parameters, and the nature of their companions. https://research-explorer.ista.ac.at/download/19844/19866/2025_AstronomyAstrophysics_Bodensteiner.pdf application/pdfno EDP Sciences2025 eng 0004-6361 1432-0746 2502.02641 00149790310001110.1051/0004-6361/202452623 698 Bodensteiner, J., Shenar, T., Sana, H., Britavskiy, N., Crowther, P. A., Langer, N., … Xu, X. T. (2025). Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be stars. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/202452623">https://doi.org/10.1051/0004-6361/202452623</a> J. Bodensteiner, T. Shenar, H. Sana, N. Britavskiy, P.A. Crowther, N. Langer, D.J. Lennon, L. Mahy, L.R. Patrick, J.I. Villaseñor, M. Abdul-Masih, D.M. Bowman, A. De Koter, S.E. De Mink, K. Deshmukh, M. Fabry, A. Gilkis, Y.L.L. Götberg, G. Holgado, R.G. Izzard, S. Janssens, V.M. Kalari, Z. Keszthelyi, J. Kubát, I. Mandel, G. Maravelias, L.M. Oskinova, D. Pauli, V. Ramachandran, D.F. Rocha, M. Renzo, A.A.C. Sander, F.R.N. Schneider, A. Schootemeijer, K. Sen, M. Stoop, S. Toonen, J.T. Van Loon, R. Valli, A. Vigna-Gómez, J.S. Vink, C. Wang, X.T. Xu, Astronomy &#38; Astrophysics 698 (2025). Bodensteiner J, Shenar T, Sana H, et al. Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be stars. <i>Astronomy &#38; Astrophysics</i>. 2025;698. doi:<a href="https://doi.org/10.1051/0004-6361/202452623">10.1051/0004-6361/202452623</a> Bodensteiner, J., T. Shenar, H. Sana, N. Britavskiy, P. A. Crowther, N. Langer, D. J. Lennon, et al. “Binarity at LOw Metallicity (BLOeM): Multiplicity Properties of Oe and Be Stars.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href="https://doi.org/10.1051/0004-6361/202452623">https://doi.org/10.1051/0004-6361/202452623</a>. Bodensteiner J, Shenar T, Sana H, Britavskiy N, Crowther PA, Langer N, Lennon DJ, Mahy L, Patrick LR, Villaseñor JI, Abdul-Masih M, Bowman DM, De Koter A, De Mink SE, Deshmukh K, Fabry M, Gilkis A, Götberg YLL, Holgado G, Izzard RG, Janssens S, Kalari VM, Keszthelyi Z, Kubát J, Mandel I, Maravelias G, Oskinova LM, Pauli D, Ramachandran V, Rocha DF, Renzo M, Sander AAC, Schneider FRN, Schootemeijer A, Sen K, Stoop M, Toonen S, Van Loon JT, Valli R, Vigna-Gómez A, Vink JS, Wang C, Xu XT. 2025. Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be stars. Astronomy &#38; Astrophysics. 698, A38. Bodensteiner, J., et al. “Binarity at LOw Metallicity (BLOeM): Multiplicity Properties of Oe and Be Stars.” <i>Astronomy &#38; Astrophysics</i>, vol. 698, A38, EDP Sciences, 2025, doi:<a href="https://doi.org/10.1051/0004-6361/202452623">10.1051/0004-6361/202452623</a>. J. Bodensteiner <i>et al.</i>, “Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be stars,” <i>Astronomy &#38; Astrophysics</i>, vol. 698. EDP Sciences, 2025. 198442025-06-15T22:01:30Z2026-04-16T08:17:17Z