[{"quality_controlled":"1","PlanS_conform":"1","OA_type":"diamond","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"ieee":"A. Schootemeijer, Y. L. L. Götberg, N. Langer, G. Bortolini, A. S. Hirschauer, and L. Patrick, “A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18,” <i>Astronomy &#38; Astrophysics</i>, vol. 707. EDP Sciences, 2026.","chicago":"Schootemeijer, Abel, Ylva Louise Linsdotter Götberg, Norbert Langer, Giacomo Bortolini, Alec S. Hirschauer, and Lee Patrick. “A Constant Upper Luminosity Limit of Cool Supergiant Stars down to the Extremely Low Metallicity of I Zw 18.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2026. <a href=\"https://doi.org/10.1051/0004-6361/202557675\">https://doi.org/10.1051/0004-6361/202557675</a>.","ista":"Schootemeijer A, Götberg YLL, Langer N, Bortolini G, Hirschauer AS, Patrick L. 2026. A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18. Astronomy &#38; Astrophysics. 707, A116.","mla":"Schootemeijer, Abel, et al. “A Constant Upper Luminosity Limit of Cool Supergiant Stars down to the Extremely Low Metallicity of I Zw 18.” <i>Astronomy &#38; Astrophysics</i>, vol. 707, A116, EDP Sciences, 2026, doi:<a href=\"https://doi.org/10.1051/0004-6361/202557675\">10.1051/0004-6361/202557675</a>.","apa":"Schootemeijer, A., Götberg, Y. L. L., Langer, N., Bortolini, G., Hirschauer, A. S., &#38; Patrick, L. (2026). A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202557675\">https://doi.org/10.1051/0004-6361/202557675</a>","ama":"Schootemeijer A, Götberg YLL, Langer N, Bortolini G, Hirschauer AS, Patrick L. A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18. <i>Astronomy &#38; Astrophysics</i>. 2026;707. doi:<a href=\"https://doi.org/10.1051/0004-6361/202557675\">10.1051/0004-6361/202557675</a>","short":"A. Schootemeijer, Y.L.L. Götberg, N. Langer, G. Bortolini, A.S. Hirschauer, L. Patrick, Astronomy &#38; Astrophysics 707 (2026)."},"file_date_updated":"2026-03-16T09:05:06Z","article_number":"A116","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"doi":"10.1051/0004-6361/202557675","has_accepted_license":"1","oa":1,"external_id":{"arxiv":["2510.12594"]},"date_updated":"2026-03-16T09:07:55Z","department":[{"_id":"YlGo"}],"publication":"Astronomy & Astrophysics","volume":707,"DOAJ_listed":"1","month":"03","article_type":"original","_id":"21450","intvolume":"       707","abstract":[{"lang":"eng","text":"Stellar wind mass loss of massive stars is often assumed to depend on their metallicity Z. Therefore, evolutionary models predict that massive stars in lower-Z environments are able to retain more of their hydrogen-rich layers and evolve into brighter cool supergiants (cool SGs; Teff < 7 kK). Surprisingly, in galaxies in the metallicity range 0.2 ≲ Z/Z⊙ ≲ 1.5, previous studies have not found a metallicity dependence on the upper luminosity limit Lmax of cool SGs. Here, we add four galaxies to the sample studied for this purpose with data from the Hubble Space Telescope and the James Webb Space Telescope (JWST). Observations of the extremely metal-poor dwarf galaxy I Zw 18 from JWST allow us to extend the studied metallicity range down to Z/Z⊙ ≈ 1/40. For cool SGs in all studied galaxies, including I Zw 18, we find a constant value of Lmax ≈ 105.6 L⊙, similar to literature results for 0.2 ≲ Z/Z⊙ ≲ 1.5. In I Zw 18 and the other studied galaxies, the presence of Wolf-Rayet stars has been previously inferred. Although we cannot rule out that some of them become intermediate-temperature objects, this paints a picture in which evolved stars with L > 105.6 L⊙ burn helium as hot, helium-rich stars down to extremely low metallicity. We argue that metallicity-independent late-phase mass loss would be the most likely mechanism responsible for this. Regardless of the exact stripping mechanism (winds or, for example, binary interaction), for the Early Universe our results imply a limitation on black hole masses and a contribution of stars born with M ≳ 30 M⊙ to its surprisingly strong nitrogen enrichment. We propose a scenario in which single stars at low metallicity emit sufficiently hard ionizing radiation to produce He II and C IV lines. In this scenario, late-phase metallicity-independent mass loss produces hot, helium-rich stars. Due to the well-understood metallicity dependence on the radiation-driven winds of hot stars, a window of opportunity would open below 0.2 Z⊙, where self-stripped helium-rich stars can exist without dense Wolf-Rayet winds that absorb hard ionizing radiation."}],"file":[{"creator":"dernst","checksum":"02a0cd932340207c96fdd3059490ad29","file_id":"21455","content_type":"application/pdf","success":1,"file_size":2102107,"date_created":"2026-03-16T09:05:06Z","relation":"main_file","date_updated":"2026-03-16T09:05:06Z","access_level":"open_access","file_name":"2026_AstronomyAstrophysics_Schootemeijer.pdf"}],"oa_version":"Published Version","title":"A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18","article_processing_charge":"No","arxiv":1,"OA_place":"publisher","year":"2026","author":[{"full_name":"Schootemeijer, Abel","first_name":"Abel","last_name":"Schootemeijer"},{"orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d"},{"full_name":"Langer, Norbert","first_name":"Norbert","last_name":"Langer"},{"full_name":"Bortolini, Giacomo","first_name":"Giacomo","last_name":"Bortolini"},{"first_name":"Alec S.","full_name":"Hirschauer, Alec S.","last_name":"Hirschauer"},{"last_name":"Patrick","full_name":"Patrick, Lee","first_name":"Lee"}],"status":"public","date_created":"2026-03-15T23:01:35Z","acknowledgement":"We thank our anonymous referee for carefully reading the manuscript and providing a constructive report with helpful feedback. This work is based in part on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with program #1233. The specific observations analyzed can be accessed via DOI: 10.17909/3c1d-6182. Moreover, this research is based in part on observations made with the NASA/ESA Hubble Space Telescope obtained from the\r\nSpace Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. These observations are associated with programs #13664, GO-10915, and DD-11307. This research was supported in part by grant NSF PHY-2309135 to the Kavli Institute for Theoretical Physics (KITP). LRP acknowledges support by grants PID2019-105552RB-C41 and PID2022-137779OB-C41 funded\r\nby MCIN/AEI/10.13039/501100011033 by “ERDF A way of making Europe”. LRP acknowledges support from grant PID2022-140483NB-C22 funded by MCIN/AEI/10.13039/501100011033.","publisher":"EDP Sciences","publication_status":"published","date_published":"2026-03-01T00:00:00Z","scopus_import":"1","language":[{"iso":"eng"}],"type":"journal_article","ddc":["520"],"day":"01"},{"article_number":"L42","file_date_updated":"2026-04-16T06:24:30Z","citation":{"ieee":"Z. Li <i>et al.</i>, “Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries,” <i>The Astrophysical Journal Letters</i>, vol. 996, no. 2. IOP Publishing, 2026.","chicago":"Li, Zhenwei, Shi Jia, Dandan Wei, Hongwei Ge, Hailiang Chen, Yangyang Zhang, Xuefei Chen, and Zhanwen Han. “Formation of Be Stars via Wind Accretion: Case Study on Black Hole + Be Star Binaries.” <i>The Astrophysical Journal Letters</i>. IOP Publishing, 2026. <a href=\"https://doi.org/10.3847/2041-8213/ae3008\">https://doi.org/10.3847/2041-8213/ae3008</a>.","apa":"Li, Z., Jia, S., Wei, D., Ge, H., Chen, H., Zhang, Y., … Han, Z. (2026). Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries. <i>The Astrophysical Journal Letters</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/2041-8213/ae3008\">https://doi.org/10.3847/2041-8213/ae3008</a>","ista":"Li Z, Jia S, Wei D, Ge H, Chen H, Zhang Y, Chen X, Han Z. 2026. Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries. The Astrophysical Journal Letters. 996(2), L42.","mla":"Li, Zhenwei, et al. “Formation of Be Stars via Wind Accretion: Case Study on Black Hole + Be Star Binaries.” <i>The Astrophysical Journal Letters</i>, vol. 996, no. 2, L42, IOP Publishing, 2026, doi:<a href=\"https://doi.org/10.3847/2041-8213/ae3008\">10.3847/2041-8213/ae3008</a>.","ama":"Li Z, Jia S, Wei D, et al. Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries. <i>The Astrophysical Journal Letters</i>. 2026;996(2). doi:<a href=\"https://doi.org/10.3847/2041-8213/ae3008\">10.3847/2041-8213/ae3008</a>","short":"Z. Li, S. Jia, D. Wei, H. Ge, H. Chen, Y. Zhang, X. Chen, Z. Han, The Astrophysical Journal Letters 996 (2026)."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","OA_type":"gold","quality_controlled":"1","has_accepted_license":"1","doi":"10.3847/2041-8213/ae3008","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_identifier":{"issn":["2041-8205"],"eissn":["2041-8213"]},"date_updated":"2026-04-16T06:26:18Z","external_id":{"arxiv":["2512.18565"]},"oa":1,"file":[{"creator":"dernst","checksum":"09200c1cf405101abdd298ce80c9a90d","file_id":"21741","content_type":"application/pdf","file_size":5202345,"date_created":"2026-04-16T06:24:30Z","success":1,"relation":"main_file","access_level":"open_access","date_updated":"2026-04-16T06:24:30Z","file_name":"2026_AstrophysicalJourLetters_Li.pdf"}],"intvolume":"       996","_id":"21714","abstract":[{"text":"Be stars are rapidly rotating main-sequence stars that play a crucial role in understanding stellar evolution and binary interactions. In this Letter, we propose a new formation scenario for black hole (BH) + Be star binaries (hereafter BHBe binaries), where the Be star is produced through the wind Roche lobe overflow (WRLOF) mechanism. Our analysis is based on numerical simulations of the WRLOF process in massive binaries, building on recent theoretical work. We demonstrate that the WRLOF model can efficiently form BHBe binaries under reasonable assumptions on stellar wind velocities. Using rapid binary population synthesis, we estimate the population of such systems in the Milky Way, predicting ∼1800−3200 currently existing BHBe binaries originating from the WRLOF channel. These systems are characterized by high eccentricities and exceptionally wide orbits, with typical orbital periods exceeding 1000 days and a peak distribution around ∼10,000 days. Due to their long orbital separations, these BHBe binaries are promising targets for future detection via astrometric and interferometric observations.","lang":"eng"}],"month":"01","article_type":"original","DOAJ_listed":"1","volume":996,"publication":"The Astrophysical Journal Letters","department":[{"_id":"YlGo"}],"author":[{"full_name":"Li, Zhenwei","first_name":"Zhenwei","last_name":"Li"},{"last_name":"Jia","first_name":"Shi","full_name":"Jia, Shi"},{"last_name":"Wei","id":"5dd129bd-0601-11ef-b325-833284687b76","first_name":"Dandan","full_name":"Wei, Dandan"},{"last_name":"Ge","first_name":"Hongwei","full_name":"Ge, Hongwei"},{"first_name":"Hailiang","full_name":"Chen, Hailiang","last_name":"Chen"},{"last_name":"Zhang","first_name":"Yangyang","full_name":"Zhang, Yangyang"},{"first_name":"Xuefei","full_name":"Chen, Xuefei","last_name":"Chen"},{"last_name":"Han","full_name":"Han, Zhanwen","first_name":"Zhanwen"}],"year":"2026","OA_place":"publisher","arxiv":1,"article_processing_charge":"Yes","title":"Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries","oa_version":"Published Version","publication_status":"published","publisher":"IOP Publishing","acknowledgement":"We are deeply grateful to the anonymous referee for the insightful comments, which have significantly improved the quality of this work. The authors express their gratitude to Zhaoyu Zuo and I. El Mellah for sharing the grids of wind accretion efficiencies. Z.L. thanks Matthias U. Kruckow for detailed discussions about the BH formation. This work is supported by the Natural Science Foundation of China (grant Nos. 12125303, 12525304, 12288102, 12090040/3, 12473034, 12503044, 12333008, 12433009, 12422305, 12273105, 12073070, 12173081), the Strategic Priority Research Program of the Chinese Academy of Sciences (grant Nos. XDB1160303, XDB1160201, XDB1160000), the National Key R&D Program of China (grant Nos. 2021YFA1600403 and 2021YFA1600400), the CAS “Light of West China,” the Yunnan Revitalization Talent Support Program-Science & Technology Champion Project (No. 202305AB350003) and Young Talent project, the International Centre of Supernovae (ICESUN), Yunnan Key Laboratory of Supernova Research (Nos. 202302AN360001 and 202201BC070003), Yunnan Fundamental Research Projects (No. 202401AT070139), and the Natural Science Foundation of Henan Province (No. 242300420944). X.C. acknowledges the New Cornerstone Science Foundation through the XPLORER PRIZE. The authors gratefully acknowledge the “PHOENIX Supercomputing Platform” jointly operated by the Binary Population Synthesis Group and the Stellar Astrophysics Group at Yunnan Observatories, Chinese Academy of Sciences.","date_created":"2026-04-12T22:01:50Z","status":"public","date_published":"2026-01-10T00:00:00Z","issue":"2","ddc":["520"],"day":"10","type":"journal_article","language":[{"iso":"eng"}],"scopus_import":"1"},{"author":[{"last_name":"Hovis-Afflerbach","first_name":"B.","full_name":"Hovis-Afflerbach, B."},{"orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"last_name":"Schootemeijer","full_name":"Schootemeijer, A.","first_name":"A."},{"last_name":"Klencki","first_name":"J.","full_name":"Klencki, J."},{"last_name":"Strom","first_name":"A. L.","full_name":"Strom, A. L."},{"last_name":"Ludwig","full_name":"Ludwig, B. A.","first_name":"B. A."},{"last_name":"Drout","first_name":"M. R.","full_name":"Drout, M. R."}],"year":"2025","OA_place":"publisher","arxiv":1,"article_processing_charge":"No","title":"The mass distribution of stars stripped in binaries: The effect of metallicity","oa_version":"Published Version","publication_status":"published","publisher":"EDP Sciences","acknowledgement":"We thank the anonymous referee for providing a constructive report. We thank Tomer Shenar and Selma de Mink for the interesting discussions that helped us improve the content of Sect. 4. Thank you to Jorick Vink and Andreas Sander for helpful discussions about wind driving. BHA thanks the Caltech Summer Undergraduate Research Fellowship (SURF) program and Peter Adams for supporting this project in memory of Alain Porter and Arthur R. Adams. BHA thanks Gwen Rudie for organizing the Carnegie Astrophysics Summer Student Internship (CASSI) program and all the staff at Carnegie Observatories who help to support this program. BHA also thanks Laura Jaliff, Sal Wanying Fu, Ivanna Escala, Johanna Teske, Tony Piro, Brian Lorenz, and Peter Senchyna for their mentorship during this project. Computing resources used for this work were made possible by a grant from the Ahmanson Foundation. We thank the Observatories of the Carnegie Institution for Science for support, including Chris Burns for help with computations. This work used computing resources provided by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. MRD acknowledges support from the NSERC through grant RGPIN-2019-06186, the Canada Research Chairs Program, and the Dunlap Institute at the University of Toronto. BHA is supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-2234667.","status":"public","date_created":"2025-06-08T22:01:22Z","date_published":"2025-05-01T00:00:00Z","ddc":["520"],"day":"01","type":"journal_article","isi":1,"language":[{"iso":"eng"}],"scopus_import":"1","article_number":"A239","file_date_updated":"2025-06-10T07:00:38Z","citation":{"chicago":"Hovis-Afflerbach, B., Ylva Louise Linsdotter Götberg, A. Schootemeijer, J. Klencki, A. L. Strom, B. A. Ludwig, and M. R. Drout. “The Mass Distribution of Stars Stripped in Binaries: The Effect of Metallicity.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href=\"https://doi.org/10.1051/0004-6361/202453185\">https://doi.org/10.1051/0004-6361/202453185</a>.","apa":"Hovis-Afflerbach, B., Götberg, Y. L. L., Schootemeijer, A., Klencki, J., Strom, A. L., Ludwig, B. A., &#38; Drout, M. R. (2025). The mass distribution of stars stripped in binaries: The effect of metallicity. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202453185\">https://doi.org/10.1051/0004-6361/202453185</a>","ista":"Hovis-Afflerbach B, Götberg YLL, Schootemeijer A, Klencki J, Strom AL, Ludwig BA, Drout MR. 2025. The mass distribution of stars stripped in binaries: The effect of metallicity. Astronomy &#38; Astrophysics. 697, A239.","mla":"Hovis-Afflerbach, B., et al. “The Mass Distribution of Stars Stripped in Binaries: The Effect of Metallicity.” <i>Astronomy &#38; Astrophysics</i>, vol. 697, A239, EDP Sciences, 2025, doi:<a href=\"https://doi.org/10.1051/0004-6361/202453185\">10.1051/0004-6361/202453185</a>.","ieee":"B. Hovis-Afflerbach <i>et al.</i>, “The mass distribution of stars stripped in binaries: The effect of metallicity,” <i>Astronomy &#38; Astrophysics</i>, vol. 697. EDP Sciences, 2025.","short":"B. Hovis-Afflerbach, Y.L.L. Götberg, A. Schootemeijer, J. Klencki, A.L. Strom, B.A. Ludwig, M.R. Drout, Astronomy &#38; Astrophysics 697 (2025).","ama":"Hovis-Afflerbach B, Götberg YLL, Schootemeijer A, et al. The mass distribution of stars stripped in binaries: The effect of metallicity. <i>Astronomy &#38; Astrophysics</i>. 2025;697. doi:<a href=\"https://doi.org/10.1051/0004-6361/202453185\">10.1051/0004-6361/202453185</a>"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","OA_type":"diamond","quality_controlled":"1","has_accepted_license":"1","doi":"10.1051/0004-6361/202453185","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"date_updated":"2026-02-16T12:10:11Z","external_id":{"isi":["001494033100007"],"arxiv":["2412.05356"]},"corr_author":"1","oa":1,"file":[{"file_id":"19799","file_size":6378030,"date_created":"2025-06-10T07:00:38Z","success":1,"content_type":"application/pdf","creator":"dernst","checksum":"caa92beb22ab3146a75c5b03e926de1f","file_name":"2025_AstronomyAstrophysics_HovisAfflerbach.pdf","relation":"main_file","date_updated":"2025-06-10T07:00:38Z","access_level":"open_access"}],"intvolume":"       697","_id":"19797","abstract":[{"text":"Stars stripped of their hydrogen-rich envelopes through binary interaction are thought to be responsible for both hydrogen-poor supernovae and the hard ionizing radiation observed in low-Z galaxies. A population of these stars was recently observed for the first time, but their prevalence remains unknown. In preparation for such measurements, we estimate the mass distribution of hot, stripped stars using a population synthesis code that interpolates over detailed single and binary stellar evolution tracks. We predict that for a constant star formation rate of 1 M⊙/yr and regardless of metallicity, a scalable model population contains ∼30 000 stripped stars with mass Mstrip > 1 M⊙ and ∼4000 stripped stars that are sufficiently massive to explode (Mstrip > 2.6 M⊙). Below Mstrip = 5 M⊙, the distribution is metallicity-independent and can be described by a power law with the exponent α ∼ −2. At higher masses and lower metallicity (Z ≲ 0.002), the mass distribution exhibits a drop. This originates from the prediction, frequently seen in evolutionary models, that massive low-metallicity stars do not expand substantially until central helium burning or later and therefore cannot form long-lived stripped stars. With weaker line-driven winds at low metallicity, this suggests that neither binary interaction nor wind mass loss can efficiently strip massive stars at low metallicity. As a result, a “helium-star desert” emerges around Mstrip = 15 M⊙ at Z = 0.002, covering an increasingly large mass range with decreasing metallicity. We note that these high-mass stars are those that potentially boost a galaxy’s He+-ionizing radiation and that participate in the formation of merging black holes. This “helium-star desert” therefore merits further study.","lang":"eng"}],"article_type":"original","month":"05","volume":697,"publication":"Astronomy & Astrophysics","department":[{"_id":"YlGo"}]},{"OA_type":"diamond","quality_controlled":"1","file_date_updated":"2025-06-25T08:38:02Z","citation":{"ieee":"N. Britavskiy <i>et al.</i>, “Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud,” <i>Astronomy &#38; Astrophysics</i>, vol. 698. EDP Sciences, 2025.","chicago":"Britavskiy, N., L. Mahy, D. J. Lennon, L. R. Patrick, H. Sana, J. I. Villaseñor, T. Shenar, et al. “Binarity at LOw Metallicity (BLOeM): Multiplicity of Early B-Type Supergiants in the Small Magellanic Cloud.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href=\"https://doi.org/10.1051/0004-6361/202452963\">https://doi.org/10.1051/0004-6361/202452963</a>.","apa":"Britavskiy, N., Mahy, L., Lennon, D. J., Patrick, L. R., Sana, H., Villaseñor, J. I., … Vink, J. S. (2025). Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202452963\">https://doi.org/10.1051/0004-6361/202452963</a>","ista":"Britavskiy N, Mahy L, Lennon DJ, Patrick LR, Sana H, Villaseñor JI, Shenar T, Bodensteiner J, Bernini-Peron M, Berlanas SR, Bowman DM, Crowther PA, De Mink SE, Evans CJ, Götberg YLL, Holgado G, Johnston C, Keszthelyi Z, Klencki J, Langer N, Mandel I, Menon A, Moe M, Oskinova LM, Pauli D, Pawlak M, Ramachandran V, Renzo M, Sander AAC, Schneider FRN, Schootemeijer A, Sen K, Simón-Díaz S, Van Loon JT, Vink JS. 2025. Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud. Astronomy &#38; Astrophysics. 698, A40.","mla":"Britavskiy, N., et al. “Binarity at LOw Metallicity (BLOeM): Multiplicity of Early B-Type Supergiants in the Small Magellanic Cloud.” <i>Astronomy &#38; Astrophysics</i>, vol. 698, A40, EDP Sciences, 2025, doi:<a href=\"https://doi.org/10.1051/0004-6361/202452963\">10.1051/0004-6361/202452963</a>.","ama":"Britavskiy N, Mahy L, Lennon DJ, et al. Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud. <i>Astronomy &#38; Astrophysics</i>. 2025;698. doi:<a href=\"https://doi.org/10.1051/0004-6361/202452963\">10.1051/0004-6361/202452963</a>","short":"N. Britavskiy, L. Mahy, D.J. Lennon, L.R. Patrick, H. Sana, J.I. Villaseñor, T. Shenar, J. Bodensteiner, M. Bernini-Peron, S.R. Berlanas, D.M. Bowman, P.A. Crowther, S.E. De Mink, C.J. Evans, Y.L.L. Götberg, G. Holgado, C. Johnston, Z. Keszthelyi, J. Klencki, N. Langer, I. Mandel, A. Menon, M. Moe, L.M. Oskinova, D. Pauli, M. Pawlak, V. Ramachandran, M. Renzo, A.A.C. Sander, F.R.N. Schneider, A. Schootemeijer, K. Sen, S. Simón-Díaz, J.T. Van Loon, J.S. Vink, Astronomy &#38; Astrophysics 698 (2025)."},"article_number":"A40","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"doi":"10.1051/0004-6361/202452963","has_accepted_license":"1","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa":1,"external_id":{"isi":["001497903100019"],"arxiv":["2502.12239"]},"date_updated":"2026-02-16T12:09:34Z","volume":698,"department":[{"_id":"YlGo"}],"publication":"Astronomy & Astrophysics","abstract":[{"lang":"eng","text":"Context. The blue supergiant (BSG) domain contains a large variety of stars whose past and future evolutionary paths are still highly uncertain. Since binary interaction plays a crucial role in the fate of massive stars, investigating the multiplicity among BSGs helps shed light on the fate of such objects.\r\nAims. We aim to estimate the binary fraction of a large sample of BSGs in the Small Magellanic Cloud (SMC) within the Binarity at LOw Metallicity (BLOeM) survey. In total, we selected 262 targets with spectral types B0-B3 and luminosity classes I-II.\r\n\r\nMethods. This work is based on spectroscopic data collected by the FLAMES instrument, mounted on the Very Large Telescope, which gathered nine epochs over three months. Our spectroscopic analysis for each target includes the individual and peak-to-peak radial velocity measurements, an investigation of the line profile variability, and a periodogram analysis to search for possible short- and long-period binaries.\r\n\r\nResults. By applying a 20 km s−1 threshold on the peak-to-peak radial velocities above which we would consider the star to be binary, the resulting observed spectroscopic binary fraction for our BSG sample is 23 ± 3%. An independent analysis of line profile variability reveals 11 (plus 5 candidates) double-lined spectroscopic binaries and 32 (plus 41 candidates) single-lined spectroscopic binaries. Based on these results, we estimated the overall observed binary fraction in this sample to be 34 ± 3%, which is close to the computed intrinsic binary fraction of 40 ± 4%. In addition, we derived reliable orbital periods for 41 spectroscopic binaries and potential binary candidates, among which there are 17 eclipsing binaries, including 20 SB1 and SB2 systems with periods of less than 10 days. We reported a significant drop in the binary fraction of BSGs with spectral types later than B2 and effective temperatures less than 18 kK, which could indicate the end of the main sequence phase in this temperature regime. We found no metallicity dependence in the binary fraction of BSGs, compared to existing spectroscopic surveys of the Galaxy and Large Magellanic Cloud."}],"_id":"19841","intvolume":"       698","file":[{"date_updated":"2025-06-25T08:38:02Z","access_level":"open_access","relation":"main_file","file_name":"2025_AstronomyAstrophysics_Britavskiy.pdf","checksum":"53a9f290cb1f468895e0d4446e0020f0","creator":"dernst","success":1,"date_created":"2025-06-25T08:38:02Z","file_size":7106568,"content_type":"application/pdf","file_id":"19901"}],"article_type":"original","month":"06","arxiv":1,"oa_version":"Published Version","article_processing_charge":"Yes","title":"Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud","year":"2025","author":[{"last_name":"Britavskiy","full_name":"Britavskiy, N.","first_name":"N."},{"full_name":"Mahy, L.","first_name":"L.","last_name":"Mahy"},{"last_name":"Lennon","full_name":"Lennon, D. J.","first_name":"D. J."},{"first_name":"L. R.","full_name":"Patrick, L. R.","last_name":"Patrick"},{"first_name":"H.","full_name":"Sana, H.","last_name":"Sana"},{"first_name":"J. I.","full_name":"Villaseñor, J. I.","last_name":"Villaseñor"},{"last_name":"Shenar","full_name":"Shenar, T.","first_name":"T."},{"first_name":"J.","full_name":"Bodensteiner, J.","last_name":"Bodensteiner"},{"first_name":"M.","full_name":"Bernini-Peron, M.","last_name":"Bernini-Peron"},{"last_name":"Berlanas","full_name":"Berlanas, S. R.","first_name":"S. R."},{"first_name":"D. M.","full_name":"Bowman, D. M.","last_name":"Bowman"},{"last_name":"Crowther","first_name":"P. A.","full_name":"Crowther, P. A."},{"first_name":"S. E.","full_name":"De Mink, S. E.","last_name":"De Mink"},{"first_name":"C. J.","full_name":"Evans, C. J.","last_name":"Evans"},{"id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg","full_name":"Götberg, Ylva Louise Linsdotter","first_name":"Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911"},{"first_name":"G.","full_name":"Holgado, G.","last_name":"Holgado"},{"full_name":"Johnston, C.","first_name":"C.","last_name":"Johnston"},{"full_name":"Keszthelyi, Z.","first_name":"Z.","last_name":"Keszthelyi"},{"last_name":"Klencki","full_name":"Klencki, J.","first_name":"J."},{"last_name":"Langer","full_name":"Langer, N.","first_name":"N."},{"first_name":"I.","full_name":"Mandel, I.","last_name":"Mandel"},{"full_name":"Menon, A.","first_name":"A.","last_name":"Menon"},{"last_name":"Moe","first_name":"M.","full_name":"Moe, M."},{"last_name":"Oskinova","first_name":"L. M.","full_name":"Oskinova, L. M."},{"last_name":"Pauli","first_name":"D.","full_name":"Pauli, D."},{"first_name":"M.","full_name":"Pawlak, M.","last_name":"Pawlak"},{"full_name":"Ramachandran, V.","first_name":"V.","last_name":"Ramachandran"},{"last_name":"Renzo","full_name":"Renzo, M.","first_name":"M."},{"last_name":"Sander","full_name":"Sander, A. A.C.","first_name":"A. A.C."},{"full_name":"Schneider, F. R.N.","first_name":"F. R.N.","last_name":"Schneider"},{"first_name":"A.","full_name":"Schootemeijer, A.","last_name":"Schootemeijer"},{"last_name":"Sen","first_name":"K.","full_name":"Sen, K."},{"first_name":"S.","full_name":"Simón-Díaz, S.","last_name":"Simón-Díaz"},{"last_name":"Van Loon","full_name":"Van Loon, J. T.","first_name":"J. T."},{"full_name":"Vink, J. S.","first_name":"J. S.","last_name":"Vink"}],"OA_place":"publisher","date_created":"2025-06-15T22:01:29Z","status":"public","acknowledgement":"We thank the anonymous referee for helpful comments that have improved the manuscript. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement 101164755/METAL) and was supported by the Israel Science Foundation (ISF) under grant number 2434/24. NB acknowledges support from the Belgian federal government grant for Ukrainian postdoctoral researchers (contract UF/2022/10). TS acknowledges support by the Israel Science Foundation (ISF) under grant number 0603225041. DP acknowledges financial support from the Deutsches Zentrum für Luft und Raumfahrt (DLR) grant FKZ 50OR2005 and the FWO junior postdoctoral fellowship No. 1256225N. DMB gratefully acknowledges UK Research and Innovation (UKRI) in the form of a Frontier Research grant under the UK government’s ERC Horizon Europe funding guarantee (SYMPHONY; PI Bowman; grant number: EP/Y031059/1), and a Royal Society University Research Fellowship (PI Bowman; grant number: URF\\R1\\231631). KS is funded by the National Science Center (NCN), Poland, under grant number OPUS 2021/41/B/ST9/00757. IM acknowledges support from the Australian Research Council (ARC) Centre of Excellence for Gravitational Wave Discovery (OzGav), through project number CE230100016. JIV acknowledges support from the European Research Council through ERC Advanced Grant No. 101054731. SS-D, and GH acknowledge support from the Spanish Ministry of Science and Innovation and Universities (MICIU) through the Spanish State Research Agency (AEI) through grants PID2021-122397NB-C21, and the Severo Ochoa Program 2020-2023 (CEX2019-000920-S).","publication_status":"published","publisher":"EDP Sciences","date_published":"2025-06-01T00:00:00Z","language":[{"iso":"eng"}],"isi":1,"scopus_import":"1","type":"journal_article","ddc":["520"],"day":"01"},{"intvolume":"       698","_id":"19842","abstract":[{"text":"Given the uncertain evolutionary status of blue supergiant stars, their multiplicity properties hold vital clues to better understand their origin and evolution. As part of The Binarity at LOw Metallicity (BLOeM) campaign in the Small Magellanic Cloud, we present a multi-epoch spectroscopic survey of 128 supergiant stars of spectral type B5–F5, which roughly correspond to initial masses in the 6–30 M⊙ range. The observed binary fraction for the B5–9 supergiants is 25 ± 6% (10 ± 4%) and 5 ± 2% (0%) for the A–F stars, which were found using a radial-velocity (RV) variability threshold of 5 km s−1 (10 km s−1) as a criterion for binarity. Accounting for observational biases, we find an intrinsic multiplicity fraction of less than 18% for the B5–9 stars and 8−7+9% for the AF stars, for the orbital periods up to 103.5 days and mass ratios (q) in the 0.1 < q < 1 range. The large stellar radii of these supergiant stars prevent short orbital periods, but we demonstrate that this effect alone cannot explain our results. We assessed the spectra and RV time series of the detected binary systems and find that only a small fraction display convincing solutions. We conclude that the multiplicity fractions are compromised by intrinsic stellar variability, such that the true multiplicity fraction may be significantly smaller. Our main conclusions from comparing the multiplicity properties of the B5–9- and AF-type supergiants to that of their less evolved counterparts is that such stars cannot be explained by a direct evolution from the main sequence. Furthermore, by comparing their multiplicity properties to red supergiant stars, we conclude that the AF supergiant stars are neither progenitors nor descendants of red supergiants.","lang":"eng"}],"file":[{"relation":"main_file","access_level":"open_access","date_updated":"2025-06-23T07:09:38Z","file_name":"2025_AstronomyAstrophysics_Patrick.pdf","creator":"dernst","checksum":"93a907bf48da7e2ba7d75b53ea6011f5","file_id":"19863","file_size":2130448,"date_created":"2025-06-23T07:09:38Z","success":1,"content_type":"application/pdf"}],"article_type":"original","month":"06","volume":698,"department":[{"_id":"YlGo"}],"publication":"Astronomy & Astrophysics","external_id":{"arxiv":["2502.02644"],"isi":["001497903100028"]},"date_updated":"2026-02-16T12:09:50Z","oa":1,"doi":"10.1051/0004-6361/202452949","has_accepted_license":"1","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"citation":{"ama":"Patrick LR, Lennon DJ, Najarro F, et al. Binarity at LOw Metallicity (BLOeM): The multiplicity properties and evolution of BAF-type supergiants. <i>Astronomy &#38; Astrophysics</i>. 2025;698. doi:<a href=\"https://doi.org/10.1051/0004-6361/202452949\">10.1051/0004-6361/202452949</a>","short":"L.R. Patrick, D.J. Lennon, F. Najarro, T. Shenar, J. Bodensteiner, H. Sana, P.A. Crowther, N. Britavskiy, N. Langer, A. Schootemeijer, C.J. Evans, L. Mahy, Y.L.L. Götberg, S.E. De Mink, F.R.N. Schneider, A.J.G. O’Grady, J.I. Villaseñor, M. Bernini-Peron, D.M. Bowman, A. De Koter, K. Deshmukh, A. Gilkis, G. González-Torà, V.M. Kalari, Z. K̃Eszthelyi, I. Mandel, A. Menon, M. Moe, L.M. Oskinova, D. Pauli, M. Renzo, A.A.C. Sander, K. Sen, M. Stoop, J.T. Van Loon, S. Toonen, F. Tramper, J.S. Vink, C. Wang, Astronomy &#38; Astrophysics 698 (2025).","ieee":"L. R. Patrick <i>et al.</i>, “Binarity at LOw Metallicity (BLOeM): The multiplicity properties and evolution of BAF-type supergiants,” <i>Astronomy &#38; Astrophysics</i>, vol. 698. EDP Sciences, 2025.","chicago":"Patrick, L. R., D. J. Lennon, F. Najarro, T. Shenar, J. Bodensteiner, H. Sana, P. A. Crowther, et al. “Binarity at LOw Metallicity (BLOeM): The Multiplicity Properties and Evolution of BAF-Type Supergiants.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href=\"https://doi.org/10.1051/0004-6361/202452949\">https://doi.org/10.1051/0004-6361/202452949</a>.","apa":"Patrick, L. R., Lennon, D. J., Najarro, F., Shenar, T., Bodensteiner, J., Sana, H., … Wang, C. (2025). Binarity at LOw Metallicity (BLOeM): The multiplicity properties and evolution of BAF-type supergiants. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202452949\">https://doi.org/10.1051/0004-6361/202452949</a>","ista":"Patrick LR, Lennon DJ, Najarro F, Shenar T, Bodensteiner J, Sana H, Crowther PA, Britavskiy N, Langer N, Schootemeijer A, Evans CJ, Mahy L, Götberg YLL, De Mink SE, Schneider FRN, O’Grady AJG, Villaseñor JI, Bernini-Peron M, Bowman DM, De Koter A, Deshmukh K, Gilkis A, González-Torà G, Kalari VM, K̃Eszthelyi Z, Mandel I, Menon A, Moe M, Oskinova LM, Pauli D, Renzo M, Sander AAC, Sen K, Stoop M, Van Loon JT, Toonen S, Tramper F, Vink JS, Wang C. 2025. Binarity at LOw Metallicity (BLOeM): The multiplicity properties and evolution of BAF-type supergiants. Astronomy &#38; Astrophysics. 698, A39.","mla":"Patrick, L. R., et al. “Binarity at LOw Metallicity (BLOeM): The Multiplicity Properties and Evolution of BAF-Type Supergiants.” <i>Astronomy &#38; Astrophysics</i>, vol. 698, A39, EDP Sciences, 2025, doi:<a href=\"https://doi.org/10.1051/0004-6361/202452949\">10.1051/0004-6361/202452949</a>."},"file_date_updated":"2025-06-23T07:09:38Z","article_number":"A39","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","OA_type":"diamond","quality_controlled":"1","type":"journal_article","ddc":["520"],"day":"01","language":[{"iso":"eng"}],"isi":1,"scopus_import":"1","date_published":"2025-06-01T00:00:00Z","publication_status":"published","publisher":"EDP Sciences","date_created":"2025-06-15T22:01:29Z","status":"public","acknowledgement":"We thank Sipra Hota for kindly sharing the SMC UVIT catalogue prior to publication. LRP, FN. and FT acknowledge support by grants PID2019-105552RB-C41 and PID2022-137779OB-C41 funded by MCIN/AEI/10.13039/501100011033 by “ERDF A way of making Europe”. LRP acknowledges support from grant PID2022-140483NB-C22 funded by MCIN/AEI/10.13039/501100011033. TS acknowledges support by the Israel Science Foundation (ISF) under grant number 0603225041. The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement numbers 772225: MULTIPLES). DMB gratefully acknowledges support from UK Research and Innovation (UKRI) in the form of a Frontier Research grant under the UK government’s ERC Horizon Europe funding guarantee (SYMPHONY; grant number: EP/Y031059/1), and a Royal Society University Research Fellowship (grant number: URF\\R1\\231631). GGT is supported by the German Deutsche Forschungsgemeinschaft (DFG) under Project-ID 496854903 (SA4064/2-1, PI Sander). AACS is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) in the form of an Emmy Noether Research Group – Project-ID 445674056 (SA4064/1-1, PI Sander). GGT and AACS further acknowledges support from the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. This paper benefited from discussions at the International Space Science Institute (ISSI) in Bern through ISSI International Team project 512 (Multiwavelength View on Massive Stars in the Era of Multimessenger Astronomy). DP acknowledges financial support by the Deutsches Zentrum für Luft und Raumfahrt (DLR) grant FKZ 50OR2005. JIV acknowledges support from the European Research Council for the ERC Advanced Grant 101054731. PAC is supported by the Science and Technology Facilities Council research grant ST/V000853/1 (PI. V. Dhillon). JSV is supported by Science and Technology Facilities Council funding under grant number ST/V000233/1. DFR is thankful for the support of the CAPES-Br and FAPERJ/DSC-10 (SEI-260003/001630/2023). This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 945806) and is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC 2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster).","year":"2025","author":[{"full_name":"Patrick, L. R.","first_name":"L. R.","last_name":"Patrick"},{"first_name":"D. J.","full_name":"Lennon, D. J.","last_name":"Lennon"},{"full_name":"Najarro, F.","first_name":"F.","last_name":"Najarro"},{"full_name":"Shenar, T.","first_name":"T.","last_name":"Shenar"},{"last_name":"Bodensteiner","first_name":"J.","full_name":"Bodensteiner, J."},{"full_name":"Sana, H.","first_name":"H.","last_name":"Sana"},{"first_name":"P. A.","full_name":"Crowther, P. A.","last_name":"Crowther"},{"last_name":"Britavskiy","first_name":"N.","full_name":"Britavskiy, N."},{"last_name":"Langer","full_name":"Langer, N.","first_name":"N."},{"first_name":"A.","full_name":"Schootemeijer, A.","last_name":"Schootemeijer"},{"last_name":"Evans","first_name":"C. J.","full_name":"Evans, C. J."},{"last_name":"Mahy","full_name":"Mahy, L.","first_name":"L."},{"orcid":"0000-0002-6960-6911","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter"},{"last_name":"De Mink","first_name":"S. E.","full_name":"De Mink, S. E."},{"full_name":"Schneider, F. R.N.","first_name":"F. R.N.","last_name":"Schneider"},{"first_name":"A. J.G.","full_name":"O’Grady, A. J.G.","last_name":"O’Grady"},{"full_name":"Villaseñor, J. I.","first_name":"J. I.","last_name":"Villaseñor"},{"last_name":"Bernini-Peron","first_name":"M.","full_name":"Bernini-Peron, M."},{"last_name":"Bowman","first_name":"D. M.","full_name":"Bowman, D. M."},{"full_name":"De Koter, A.","first_name":"A.","last_name":"De Koter"},{"last_name":"Deshmukh","first_name":"K.","full_name":"Deshmukh, K."},{"first_name":"A.","full_name":"Gilkis, A.","last_name":"Gilkis"},{"last_name":"González-Torà","full_name":"González-Torà, G.","first_name":"G."},{"last_name":"Kalari","full_name":"Kalari, V. M.","first_name":"V. M."},{"full_name":"K̃Eszthelyi, Z.","first_name":"Z.","last_name":"K̃Eszthelyi"},{"last_name":"Mandel","full_name":"Mandel, I.","first_name":"I."},{"last_name":"Menon","full_name":"Menon, A.","first_name":"A."},{"first_name":"M.","full_name":"Moe, M.","last_name":"Moe"},{"last_name":"Oskinova","first_name":"L. M.","full_name":"Oskinova, L. M."},{"last_name":"Pauli","full_name":"Pauli, D.","first_name":"D."},{"last_name":"Renzo","full_name":"Renzo, M.","first_name":"M."},{"first_name":"A. A.C.","full_name":"Sander, A. A.C.","last_name":"Sander"},{"first_name":"K.","full_name":"Sen, K.","last_name":"Sen"},{"last_name":"Stoop","full_name":"Stoop, M.","first_name":"M."},{"last_name":"Van Loon","first_name":"J. T.","full_name":"Van Loon, J. T."},{"last_name":"Toonen","full_name":"Toonen, S.","first_name":"S."},{"full_name":"Tramper, F.","first_name":"F.","last_name":"Tramper"},{"last_name":"Vink","first_name":"J. S.","full_name":"Vink, J. S."},{"last_name":"Wang","first_name":"C.","full_name":"Wang, C."}],"OA_place":"publisher","arxiv":1,"oa_version":"Published Version","article_processing_charge":"Yes","title":"Binarity at LOw Metallicity (BLOeM): The multiplicity properties and evolution of BAF-type supergiants"},{"external_id":{"isi":["001568077900001"],"arxiv":["2509.12488"]},"date_updated":"2025-12-30T10:27:05Z","oa":1,"abstract":[{"lang":"eng","text":"At high metallicity, a majority of massive stars have at least one close stellar companion. The evolution of such binaries is subject to strong interaction processes, which heavily impact the characteristics of their life-ending supernova and compact remnants. For the low-metallicity environments of high-redshift galaxies, constraints on the multiplicity properties of massive stars over the separation range leading to binary interaction are crucially missing. Here we show that the presence of massive stars in close binaries is ubiquitous, even at low metallicity. Using the Very Large Telescope, we obtained multi-epoch radial velocity measurements of a representative sample of 139 massive O-type stars across the Small Magellanic Cloud, which has a metal content of about one-fifth of the solar value. We find that 45% of them show radial velocity variations that demonstrate that they are members of close binary systems, and predominantly have orbital periods shorter than 1 year. Correcting for observational biases indicates that at least 70+11−6 %  of the O stars in our sample are in close binaries, and that at least 68+7\r\n−8% of all O stars interact with a companion star during their lifetime. We found no evidence supporting a statistically significant trend of the multiplicity properties with metallicity. Our results indicate that multiplicity and binary interactions govern the evolution of massive stars and determine their cosmic feedback and explosive fates."}],"_id":"20352","intvolume":"         9","article_type":"original","month":"09","volume":9,"department":[{"_id":"YlGo"}],"publication":"Nature Astronomy","citation":{"mla":"Sana, H., et al. “A High Fraction of Close Massive Binary Stars at Low Metallicity.” <i>Nature Astronomy</i>, vol. 9, Springer Nature, 2025, pp. 1337–46, doi:<a href=\"https://doi.org/10.1038/s41550-025-02610-x\">10.1038/s41550-025-02610-x</a>.","apa":"Sana, H., Shenar, T., Bodensteiner, J., Britavskiy, N., Langer, N., Lennon, D. J., … Willcox, R. (2025). A high fraction of close massive binary stars at low metallicity. <i>Nature Astronomy</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41550-025-02610-x\">https://doi.org/10.1038/s41550-025-02610-x</a>","ista":"Sana H, Shenar T, Bodensteiner J, Britavskiy N, Langer N, Lennon DJ, Mahy L, Mandel I, De Mink SE, Patrick LR, Villaseñor JI, Dirickx M, Abdul-Masih M, Almeida LA, Backs F, Berlanas SR, Bernini-Peron M, Bowman DM, Bronner VA, Crowther PA, Deshmukh K, Evans CJ, Fabry M, Gieles M, Gilkis A, González-Torà G, Gräfener G, Götberg YLL, Hawcroft C, Hénault-Brunet V, Herrero A, Holgado G, Izzard RG, De Koter A, Janssens S, Johnston C, Josiek J, Justham S, Kalari VM, Klencki J, Kubát J, Kubátová B, Lefever RR, Van Loon JT, Ludwig B, Mackey J, Maíz Apellániz J, Maravelias G, Marchant P, Mazeh T, Menon A, Moe M, Najarro F, Oskinova LM, Ovadia R, Pauli D, Pawlak M, Ramachandran V, Renzo M, Rocha DF, Sander AAC, Schneider FRN, Schootemeijer A, Schösser EC, Schürmann C, Sen K, Shahaf S, Simón-Díaz S, Van Son LAC, Stoop M, Toonen S, Tramper F, Valli R, Vigna-Gómez A, Vink JS, Wang C, Willcox R. 2025. A high fraction of close massive binary stars at low metallicity. Nature Astronomy. 9, 1337–1346.","chicago":"Sana, H., T. Shenar, J. Bodensteiner, N. Britavskiy, N. Langer, D. J. Lennon, L. Mahy, et al. “A High Fraction of Close Massive Binary Stars at Low Metallicity.” <i>Nature Astronomy</i>. Springer Nature, 2025. <a href=\"https://doi.org/10.1038/s41550-025-02610-x\">https://doi.org/10.1038/s41550-025-02610-x</a>.","ieee":"H. Sana <i>et al.</i>, “A high fraction of close massive binary stars at low metallicity,” <i>Nature Astronomy</i>, vol. 9. Springer Nature, pp. 1337–1346, 2025.","short":"H. Sana, T. Shenar, J. Bodensteiner, N. Britavskiy, N. Langer, D.J. Lennon, L. Mahy, I. Mandel, S.E. De Mink, L.R. Patrick, J.I. Villaseñor, M. Dirickx, M. Abdul-Masih, L.A. Almeida, F. Backs, S.R. Berlanas, M. Bernini-Peron, D.M. Bowman, V.A. Bronner, P.A. Crowther, K. Deshmukh, C.J. Evans, M. Fabry, M. Gieles, A. Gilkis, G. González-Torà, G. Gräfener, Y.L.L. Götberg, C. Hawcroft, V. Hénault-Brunet, A. Herrero, G. Holgado, R.G. Izzard, A. De Koter, S. Janssens, C. Johnston, J. Josiek, S. Justham, V.M. Kalari, J. Klencki, J. Kubát, B. Kubátová, R.R. Lefever, J.T. Van Loon, B. Ludwig, J. Mackey, J. Maíz Apellániz, G. Maravelias, P. Marchant, T. Mazeh, A. Menon, M. Moe, F. Najarro, L.M. Oskinova, R. Ovadia, D. Pauli, M. Pawlak, V. Ramachandran, M. Renzo, D.F. Rocha, A.A.C. Sander, F.R.N. Schneider, A. Schootemeijer, E.C. Schösser, C. Schürmann, K. Sen, S. Shahaf, S. Simón-Díaz, L.A.C. Van Son, M. Stoop, S. Toonen, F. Tramper, R. Valli, A. Vigna-Gómez, J.S. Vink, C. Wang, R. Willcox, Nature Astronomy 9 (2025) 1337–1346.","ama":"Sana H, Shenar T, Bodensteiner J, et al. A high fraction of close massive binary stars at low metallicity. <i>Nature Astronomy</i>. 2025;9:1337-1346. doi:<a href=\"https://doi.org/10.1038/s41550-025-02610-x\">10.1038/s41550-025-02610-x</a>"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.2509.12488","open_access":"1"}],"OA_type":"green","quality_controlled":"1","doi":"10.1038/s41550-025-02610-x","publication_identifier":{"eissn":["2397-3366"]},"date_published":"2025-09-02T00:00:00Z","type":"journal_article","day":"02","page":"1337-1346","language":[{"iso":"eng"}],"isi":1,"scopus_import":"1","year":"2025","author":[{"full_name":"Sana, H.","first_name":"H.","last_name":"Sana"},{"first_name":"T.","full_name":"Shenar, T.","last_name":"Shenar"},{"last_name":"Bodensteiner","first_name":"J.","full_name":"Bodensteiner, J."},{"last_name":"Britavskiy","first_name":"N.","full_name":"Britavskiy, N."},{"last_name":"Langer","full_name":"Langer, N.","first_name":"N."},{"full_name":"Lennon, D. J.","first_name":"D. J.","last_name":"Lennon"},{"first_name":"L.","full_name":"Mahy, L.","last_name":"Mahy"},{"last_name":"Mandel","first_name":"I.","full_name":"Mandel, I."},{"last_name":"De Mink","full_name":"De Mink, S. E.","first_name":"S. E."},{"last_name":"Patrick","first_name":"L. R.","full_name":"Patrick, L. R."},{"first_name":"J. I.","full_name":"Villaseñor, J. I.","last_name":"Villaseñor"},{"full_name":"Dirickx, M.","first_name":"M.","last_name":"Dirickx"},{"last_name":"Abdul-Masih","first_name":"M.","full_name":"Abdul-Masih, M."},{"last_name":"Almeida","first_name":"L. A.","full_name":"Almeida, L. A."},{"last_name":"Backs","first_name":"F.","full_name":"Backs, F."},{"first_name":"S. R.","full_name":"Berlanas, S. R.","last_name":"Berlanas"},{"last_name":"Bernini-Peron","full_name":"Bernini-Peron, M.","first_name":"M."},{"last_name":"Bowman","full_name":"Bowman, D. M.","first_name":"D. M."},{"full_name":"Bronner, V. A.","first_name":"V. A.","last_name":"Bronner"},{"last_name":"Crowther","first_name":"P. A.","full_name":"Crowther, P. A."},{"first_name":"K.","full_name":"Deshmukh, K.","last_name":"Deshmukh"},{"first_name":"C. J.","full_name":"Evans, C. J.","last_name":"Evans"},{"full_name":"Fabry, M.","first_name":"M.","last_name":"Fabry"},{"first_name":"M.","full_name":"Gieles, M.","last_name":"Gieles"},{"full_name":"Gilkis, A.","first_name":"A.","last_name":"Gilkis"},{"last_name":"González-Torà","first_name":"G.","full_name":"González-Torà, G."},{"full_name":"Gräfener, G.","first_name":"G.","last_name":"Gräfener"},{"first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg","orcid":"0000-0002-6960-6911"},{"last_name":"Hawcroft","full_name":"Hawcroft, C.","first_name":"C."},{"full_name":"Hénault-Brunet, V.","first_name":"V.","last_name":"Hénault-Brunet"},{"last_name":"Herrero","first_name":"A.","full_name":"Herrero, A."},{"last_name":"Holgado","first_name":"G.","full_name":"Holgado, G."},{"last_name":"Izzard","full_name":"Izzard, R. G.","first_name":"R. G."},{"last_name":"De Koter","first_name":"A.","full_name":"De Koter, A."},{"last_name":"Janssens","first_name":"S.","full_name":"Janssens, S."},{"last_name":"Johnston","full_name":"Johnston, C.","first_name":"C."},{"first_name":"J.","full_name":"Josiek, J.","last_name":"Josiek"},{"first_name":"S.","full_name":"Justham, S.","last_name":"Justham"},{"last_name":"Kalari","full_name":"Kalari, V. M.","first_name":"V. M."},{"first_name":"J.","full_name":"Klencki, J.","last_name":"Klencki"},{"full_name":"Kubát, J.","first_name":"J.","last_name":"Kubát"},{"last_name":"Kubátová","full_name":"Kubátová, B.","first_name":"B."},{"full_name":"Lefever, R. R.","first_name":"R. R.","last_name":"Lefever"},{"first_name":"J. Th","full_name":"Van Loon, J. Th","last_name":"Van Loon"},{"first_name":"B.","full_name":"Ludwig, B.","last_name":"Ludwig"},{"first_name":"J.","full_name":"Mackey, J.","last_name":"Mackey"},{"first_name":"J.","full_name":"Maíz Apellániz, J.","last_name":"Maíz Apellániz"},{"last_name":"Maravelias","full_name":"Maravelias, G.","first_name":"G."},{"last_name":"Marchant","full_name":"Marchant, P.","first_name":"P."},{"full_name":"Mazeh, T.","first_name":"T.","last_name":"Mazeh"},{"last_name":"Menon","full_name":"Menon, A.","first_name":"A."},{"last_name":"Moe","full_name":"Moe, M.","first_name":"M."},{"last_name":"Najarro","first_name":"F.","full_name":"Najarro, F."},{"first_name":"L. M.","full_name":"Oskinova, L. M.","last_name":"Oskinova"},{"full_name":"Ovadia, R.","first_name":"R.","last_name":"Ovadia"},{"full_name":"Pauli, D.","first_name":"D.","last_name":"Pauli"},{"last_name":"Pawlak","full_name":"Pawlak, M.","first_name":"M."},{"last_name":"Ramachandran","first_name":"V.","full_name":"Ramachandran, V."},{"last_name":"Renzo","full_name":"Renzo, M.","first_name":"M."},{"last_name":"Rocha","first_name":"D. F.","full_name":"Rocha, D. F."},{"last_name":"Sander","first_name":"A. A.C.","full_name":"Sander, A. A.C."},{"first_name":"F. R.N.","full_name":"Schneider, F. R.N.","last_name":"Schneider"},{"full_name":"Schootemeijer, A.","first_name":"A.","last_name":"Schootemeijer"},{"last_name":"Schösser","full_name":"Schösser, E. C.","first_name":"E. C."},{"last_name":"Schürmann","first_name":"C.","full_name":"Schürmann, C."},{"last_name":"Sen","first_name":"K.","full_name":"Sen, K."},{"last_name":"Shahaf","first_name":"S.","full_name":"Shahaf, S."},{"first_name":"S.","full_name":"Simón-Díaz, S.","last_name":"Simón-Díaz"},{"last_name":"Van Son","full_name":"Van Son, L. A.C.","first_name":"L. A.C."},{"full_name":"Stoop, M.","first_name":"M.","last_name":"Stoop"},{"first_name":"S.","full_name":"Toonen, S.","last_name":"Toonen"},{"full_name":"Tramper, F.","first_name":"F.","last_name":"Tramper"},{"first_name":"R.","full_name":"Valli, R.","last_name":"Valli"},{"first_name":"A.","full_name":"Vigna-Gómez, A.","last_name":"Vigna-Gómez"},{"full_name":"Vink, J. S.","first_name":"J. S.","last_name":"Vink"},{"first_name":"C.","full_name":"Wang, C.","last_name":"Wang"},{"last_name":"Willcox","full_name":"Willcox, R.","first_name":"R."}],"OA_place":"repository","arxiv":1,"oa_version":"Preprint","title":"A high fraction of close massive binary stars at low metallicity","article_processing_charge":"No","publication_status":"published","publisher":"Springer Nature","status":"public","date_created":"2025-09-14T22:01:32Z","acknowledgement":"Based on data collected at the European Southern Observatory (ESO) under programme ID 112.25R7. The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 and Horizon Europe research and innovation programme (grant agreement numbers 772225: MULTIPLES, 772086: ASSESS and 945806: TEL-STARS, ADG101054731: Stellar-BHs-SDSS-V, and 101164755: METAL). This research was supported by the Israel Science Foundation (ISF) under grant number 0603225041. We acknowledge support from the Science and Technology Facilities Council (research grant ST/V000853/1 and ST/V000233/1), UK Research and Innovation (UKRI) and the UK government’s ERC Horizon Europe funding guarantee (grant number EP/Y031059/1), a Royal Society University Research Fellowship (grant number URF\\R1\\231631), a Royal Society–Science Foundation Ireland University Research Fellowship, the German Deutsche Forschungsgemeinschaft (Project-ID 496854903, 445674056 and 443790621, Germany’s Excellence Strategy EXC 2181/1-390900948), the Klaus Tschira Foundation, the JSPS Kakenhi Grant-in-Aid for Scientific Research (23K19071) and international fellowships (at the Graduate school of Science, Tokyo University), the Australian Research Council (ARC) Centre of Excellence for Gravitational Wave Discovery (OzGrav; project number CE230100016), the Deutsches Zentrum für Luft und Raumfahrt (DLR) grants FKZ 50OR2005 and 50OR2306, Agencia Española de Investigación (AEI) of the Spanish Ministerio de Ciencia Innovación y Universidades (MICIU) and the European Regional Development Fund, FEDER and Severo Ochoa Programme (grants PID2021-122397NB-C21 and CEX2019-000920-S), the NextGeneration EU/PRTR and MIU (UNI/551/2021) trough grant Margarita Salas-UL, the CAPES-Br and FAPERJ/DSC-10 (SEI-260003/001630/2023), MCIN/AEI/10.13039/501100011033 by ‘ERDF A way of making Europe’ (grants PID2019-105552RB-C41 and PID2022-137779OB-C41, PID2021-125485NB-C22, CEX2019-000918-M) funded by MCIN/AEI/10.13039/501100011033 (State Agency for Research of the Spanish Ministry of Science and Innovation) and SGR-2021-01069 (AGAUR), the Spanish Government Ministerio de Ciencia e Innovación and Agencia Estatal de Investigación (10.13 039/501 100 011 033; grant PID2022-136 640 NB-C22), the Consejo Superior de Investigaciones Científicas (CSIC; grant 2022-AEP 005), the Polish National Agency for Academic Exchange (BEKKER fellowship BPN/BEK/2022/1/00106) and National Science Center (NCN, Poland; grant number OPUS 2021/41/B/ST9/00757), the ‘La Caixa’ Foundation (ID 100010434) under the fellowship code LCF/BQ/PI23/11970035, the Research foundation Flanders (FWO) PhD fellowship under project 11E1721N and senior postdoctoral fellowship under number 12ZY523N, and the Netherlands Research Council NWO (VIDI 203.061 grant)."},{"OA_type":"gold","PlanS_conform":"1","quality_controlled":"1","file_date_updated":"2025-12-30T07:24:34Z","citation":{"ieee":"Z. Xing, S. Torres Rodriguez, Y. L. L. Götberg, A. A. Trani, V. Korol, and J. Cuadra, “Combining REBOUND and MESA: Dynamical evolution of planets orbiting interacting binaries,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 537, no. 1. Oxford University Press, pp. 285–292, 2025.","ista":"Xing Z, Torres Rodriguez S, Götberg YLL, Trani AA, Korol V, Cuadra J. 2025. Combining REBOUND and MESA: Dynamical evolution of planets orbiting interacting binaries. Monthly Notices of the Royal Astronomical Society. 537(1), 285–292.","apa":"Xing, Z., Torres Rodriguez, S., Götberg, Y. L. L., Trani, A. A., Korol, V., &#38; Cuadra, J. (2025). Combining REBOUND and MESA: Dynamical evolution of planets orbiting interacting binaries. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stae2820\">https://doi.org/10.1093/mnras/stae2820</a>","mla":"Xing, Zepei, et al. “Combining REBOUND and MESA: Dynamical Evolution of Planets Orbiting Interacting Binaries.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 537, no. 1, Oxford University Press, 2025, pp. 285–92, doi:<a href=\"https://doi.org/10.1093/mnras/stae2820\">10.1093/mnras/stae2820</a>.","chicago":"Xing, Zepei, Santiago Torres Rodriguez, Ylva Louise Linsdotter Götberg, Alessandro A. Trani, Valeriya Korol, and Jorge Cuadra. “Combining REBOUND and MESA: Dynamical Evolution of Planets Orbiting Interacting Binaries.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2025. <a href=\"https://doi.org/10.1093/mnras/stae2820\">https://doi.org/10.1093/mnras/stae2820</a>.","ama":"Xing Z, Torres Rodriguez S, Götberg YLL, Trani AA, Korol V, Cuadra J. Combining REBOUND and MESA: Dynamical evolution of planets orbiting interacting binaries. <i>Monthly Notices of the Royal Astronomical Society</i>. 2025;537(1):285-292. doi:<a href=\"https://doi.org/10.1093/mnras/stae2820\">10.1093/mnras/stae2820</a>","short":"Z. Xing, S. Torres Rodriguez, Y.L.L. Götberg, A.A. Trani, V. Korol, J. Cuadra, Monthly Notices of the Royal Astronomical Society 537 (2025) 285–292."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"has_accepted_license":"1","doi":"10.1093/mnras/stae2820","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa":1,"date_updated":"2025-12-30T07:25:37Z","external_id":{"isi":["001400731500001"],"arxiv":["2410.19695"]},"DOAJ_listed":"1","volume":537,"publication":"Monthly Notices of the Royal Astronomical Society","department":[{"_id":"YlGo"},{"_id":"LiBu"}],"file":[{"date_updated":"2025-12-30T07:24:34Z","access_level":"open_access","relation":"main_file","file_name":"2025_MonthlyNoticesRAS_Xing.pdf","checksum":"49fb4fe69f487d36169ccea60acbeccc","creator":"dernst","file_size":2974244,"date_created":"2025-12-30T07:24:34Z","success":1,"content_type":"application/pdf","file_id":"20881"}],"intvolume":"       537","_id":"18984","abstract":[{"lang":"eng","text":"Although planets have been found orbiting binary systems, whether they can survive binary interactions is debated. While the tightest-orbit binaries should host the most dynamically stable and long-lived circumbinary planetary systems, they are also the systems that are expected to experience mass transfer, common envelope evolution, or stellar mergers. In this study, we explore the effect of stable non-conservative mass transfer on the dynamical evolution of circumbinary planets. We present a new script that seamlessly integrates binary evolution data from the 1D binary stellar evolution code MESA into the N-body simulation code REBOUND. This integration framework enables a comprehensive examination of the dynamical evolution of circumbinary planets orbiting mass-transferring binaries, while simultaneously accounting for the detailed stellar structure evolution. In addition, we introduce a recalibration method to mitigate numerical errors from updates of binary properties during the system's dynamical evolution. We construct a reference binary model in which a 2.21M⊙ star loses its hydrogen-rich envelope through non-conservative mass transfer to the 1.76M⊙ companion star, creating a 0.38M⊙ subdwarf. We find the tightest stable orbital separation for circumbinary planets to be ≃2.5 times the binary separation after mass transfer. Accounting for tides by using the interior stellar structure, we find that tidal effects become apparent after the rapid mass transfer phase and start to fade away during the latter stage of the slow mass transfer phase. Our research provides a new framework for exploring circumbinary planet dynamics in interacting binary systems."}],"month":"02","article_type":"original","arxiv":1,"article_processing_charge":"Yes","title":"Combining REBOUND and MESA: Dynamical evolution of planets orbiting interacting binaries","oa_version":"Published Version","ec_funded":1,"author":[{"last_name":"Xing","first_name":"Zepei","full_name":"Xing, Zepei"},{"id":"a8df4360-4328-11ee-8f1a-e502d0c83fc2","last_name":"Torres Rodriguez","full_name":"Torres Rodriguez, Santiago","first_name":"Santiago","orcid":"0000-0002-3150-8988"},{"orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"full_name":"Trani, Alessandro A.","first_name":"Alessandro A.","last_name":"Trani"},{"full_name":"Korol, Valeriya","first_name":"Valeriya","last_name":"Korol"},{"full_name":"Cuadra, Jorge","first_name":"Jorge","last_name":"Cuadra"}],"year":"2025","OA_place":"publisher","acknowledgement":"We thank the participants of the 2023 Kavli Summer Program in Astrophysics, hosted by the Max Planck Institute for Astrophysics and funded by the Kavli Foundation. In particular, Holly Preece, Selma de Mink, and Stephen Justham for their feedback and comments on our work. ZX acknowledges support from the China Scholarship Council (CSC). ST acknowledges the funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101034413. AAT acknowledges support from the Horizon Europe research and innovation programmes under the Marie Skłodowska-Curie grant agreement no. 101103134.","status":"public","date_created":"2025-02-02T23:01:53Z","project":[{"call_identifier":"H2020","_id":"fc2ed2f7-9c52-11eb-aca3-c01059dda49c","grant_number":"101034413","name":"IST-BRIDGE: International postdoctoral program"}],"publication_status":"published","publisher":"Oxford University Press","issue":"1","date_published":"2025-02-01T00:00:00Z","isi":1,"language":[{"iso":"eng"}],"scopus_import":"1","ddc":["520"],"day":"01","page":"285-292","type":"journal_article"},{"scopus_import":"1","isi":1,"language":[{"iso":"eng"}],"day":"01","ddc":["520"],"type":"journal_article","date_published":"2025-06-01T00:00:00Z","acknowledgement":"The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 and Horizon Europe research and innovation programme (grant agreement numbers 772225: MULTIPLES, and 945806) and is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC 2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). DMB gratefully acknowledges funding from UK Research and Innovation (UKRI) in the form of a Frontier Research grant under the UK government’s ERC Horizon Europe funding guarantee (SYMPHONY; grant number: EP/Y031059/1), and a Royal Society University Research Fellowship (URF; grant number: URF\\R1\\231631). RGI is funded by STFC grant ST/Y002350/1 as part of the BRIDGCE UK network, and thanks IReNA colleagues for stimulating discussions. Z.K. acknowledges support from JSPS Kakenhi Grant-in-Aid for Scientific Research (23K19071). IM acknowledges support from the Australian Research Council (ARC) Centre of Excellence for GravitationalWave Discovery (OzGrav), through project number CE230100016. DP acknowledges financial support by the Deutsches Zentrum für Luft und Raumfahrt (DLR) grant FKZ 50OR2005. DFR is thankful for the support of CAPES-Br and FAPERJ/DSC-10 (SEI-260003/001630/2023). AACS and VR are supported by the German Deutsche Forschungsgemeinschaft (DFG) under Project-ID 445674056 (Emmy Noether Research Group SA4064/1-1, PI Sander). AACS and VR are further supported by funding from the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. JIV acknowledges support from the European Research Council for the ERC Advanced Grant 101054731. LRP acknowledges support from grant PID2022-140483NB-C22 funded by MCIN/AEI/10.13039/501100011033. GH acknowledges support from grants PID2021-122397NB-C21/PID2022-136640NB-C22 funded by MCIN/AEI/FEDER/10.13039/501100011033. J.K. thanks for the support of a grant GA CR 22-34467S. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement 101164755/METAL) and was supported by the Israel Science Foundation (ISF) under grant number 2434/24.","date_created":"2025-06-15T22:01:30Z","status":"public","publisher":"EDP Sciences","publication_status":"published","title":"Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be stars","article_processing_charge":"Yes","oa_version":"Published Version","arxiv":1,"OA_place":"publisher","author":[{"first_name":"J.","full_name":"Bodensteiner, J.","last_name":"Bodensteiner"},{"first_name":"T.","full_name":"Shenar, T.","last_name":"Shenar"},{"first_name":"H.","full_name":"Sana, H.","last_name":"Sana"},{"first_name":"N.","full_name":"Britavskiy, N.","last_name":"Britavskiy"},{"last_name":"Crowther","full_name":"Crowther, P. A.","first_name":"P. A."},{"first_name":"N.","full_name":"Langer, N.","last_name":"Langer"},{"last_name":"Lennon","first_name":"D. J.","full_name":"Lennon, D. J."},{"first_name":"L.","full_name":"Mahy, L.","last_name":"Mahy"},{"full_name":"Patrick, L. R.","first_name":"L. R.","last_name":"Patrick"},{"last_name":"Villaseñor","full_name":"Villaseñor, J. I.","first_name":"J. I."},{"full_name":"Abdul-Masih, M.","first_name":"M.","last_name":"Abdul-Masih"},{"last_name":"Bowman","first_name":"D. M.","full_name":"Bowman, D. M."},{"last_name":"De Koter","first_name":"A.","full_name":"De Koter, A."},{"first_name":"S. E.","full_name":"De Mink, S. E.","last_name":"De Mink"},{"first_name":"K.","full_name":"Deshmukh, K.","last_name":"Deshmukh"},{"full_name":"Fabry, M.","first_name":"M.","last_name":"Fabry"},{"last_name":"Gilkis","full_name":"Gilkis, A.","first_name":"A."},{"orcid":"0000-0002-6960-6911","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","full_name":"Götberg, Ylva Louise Linsdotter","first_name":"Ylva Louise Linsdotter"},{"last_name":"Holgado","full_name":"Holgado, G.","first_name":"G."},{"first_name":"R. G.","full_name":"Izzard, R. G.","last_name":"Izzard"},{"last_name":"Janssens","full_name":"Janssens, S.","first_name":"S."},{"last_name":"Kalari","full_name":"Kalari, V. M.","first_name":"V. M."},{"last_name":"Keszthelyi","first_name":"Z.","full_name":"Keszthelyi, Z."},{"last_name":"Kubát","full_name":"Kubát, J.","first_name":"J."},{"last_name":"Mandel","first_name":"I.","full_name":"Mandel, I."},{"last_name":"Maravelias","full_name":"Maravelias, G.","first_name":"G."},{"full_name":"Oskinova, L. M.","first_name":"L. M.","last_name":"Oskinova"},{"first_name":"D.","full_name":"Pauli, D.","last_name":"Pauli"},{"full_name":"Ramachandran, V.","first_name":"V.","last_name":"Ramachandran"},{"first_name":"D. F.","full_name":"Rocha, D. F.","last_name":"Rocha"},{"last_name":"Renzo","full_name":"Renzo, M.","first_name":"M."},{"full_name":"Sander, A. A.C.","first_name":"A. A.C.","last_name":"Sander"},{"full_name":"Schneider, F. R.N.","first_name":"F. R.N.","last_name":"Schneider"},{"first_name":"A.","full_name":"Schootemeijer, A.","last_name":"Schootemeijer"},{"full_name":"Sen, K.","first_name":"K.","last_name":"Sen"},{"last_name":"Stoop","full_name":"Stoop, M.","first_name":"M."},{"full_name":"Toonen, S.","first_name":"S.","last_name":"Toonen"},{"last_name":"Van Loon","full_name":"Van Loon, J. T.","first_name":"J. T."},{"last_name":"Valli","full_name":"Valli, R.","first_name":"R."},{"last_name":"Vigna-Gómez","first_name":"A.","full_name":"Vigna-Gómez, A."},{"last_name":"Vink","full_name":"Vink, J. S.","first_name":"J. S."},{"first_name":"C.","full_name":"Wang, C.","last_name":"Wang"},{"last_name":"Xu","first_name":"X. T.","full_name":"Xu, X. T."}],"year":"2025","publication":"Astronomy & Astrophysics","department":[{"_id":"YlGo"}],"volume":698,"article_type":"original","month":"06","file":[{"file_id":"19866","content_type":"application/pdf","file_size":2404827,"success":1,"date_created":"2025-06-23T07:54:57Z","creator":"dernst","checksum":"51d79c82f6030180fb7c5d7ba01b2da8","file_name":"2025_AstronomyAstrophysics_Bodensteiner.pdf","relation":"main_file","access_level":"open_access","date_updated":"2025-06-23T07:54:57Z"}],"_id":"19844","intvolume":"       698","abstract":[{"text":"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.\r\n\r\nAims. 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.\r\n\r\nMethods. 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.\r\n\r\nResults. 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.\r\n\r\nConclusions. 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.","lang":"eng"}],"oa":1,"date_updated":"2026-04-16T08:17:17Z","external_id":{"isi":["001497903100011"],"arxiv":["2502.02641"]},"publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"has_accepted_license":"1","doi":"10.1051/0004-6361/202452623","quality_controlled":"1","OA_type":"diamond","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","article_number":"A38","citation":{"ama":"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>","short":"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).","ieee":"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.","chicago":"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>.","apa":"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>","mla":"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>.","ista":"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."},"file_date_updated":"2025-06-23T07:54:57Z"},{"article_type":"original","month":"09","file":[{"file_name":"2024_AstrophysicalJourn_Mockler.pdf","date_updated":"2024-09-30T08:54:26Z","access_level":"open_access","relation":"main_file","file_size":844227,"success":1,"date_created":"2024-09-30T08:54:26Z","content_type":"application/pdf","file_id":"18161","checksum":"050ddf873244839825714cca42b5d857","creator":"dernst"}],"intvolume":"       973","_id":"18111","abstract":[{"text":"Observations of tidal disruption events (TDEs) show signs of nitrogen enrichment reminiscent of other astrophysical sources such as active galactic nuclei and star-forming galaxies. Given that TDEs probe the gas from a single star, it is possible to test whether the observed enrichment is consistent with expectations from the CNO cycle by looking at the observed nitrogen/carbon (N/C) abundance ratios. Given that ≈20% of solar-mass stars (and an even larger fraction of more massive stars) live in close binaries, it is worthwhile to also consider what TDEs from stars influenced by binary evolution would look like. We show here that TDEs from stars stripped of their hydrogen-rich (and nitrogen-poor) envelopes through previous binary-induced mass loss can produce much higher observable N/C enhancements than even TDEs from massive stars. Additionally, we predict that the time dependence of the N/C abundance ratio in the mass fallback rate of stripped stars will follow the inverse behavior of main-sequence stars, enabling a more accurate characterization of the disrupted star.","lang":"eng"}],"publication":"Astrophysical Journal Letters","department":[{"_id":"YlGo"}],"DOAJ_listed":"1","volume":973,"date_updated":"2025-09-08T09:48:50Z","external_id":{"isi":["001310592900001"]},"oa":1,"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"has_accepted_license":"1","doi":"10.3847/2041-8213/ad6c34","publication_identifier":{"issn":["2041-8205"],"eissn":["2041-8213"]},"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","article_number":"L9","file_date_updated":"2024-09-30T08:54:26Z","citation":{"ieee":"B. Mockler, M. Gallegos-Garcia, Y. L. L. Götberg, J. M. Miller, and E. Ramirez-Ruiz, “Tidal disruption events from stripped stars,” <i>Astrophysical Journal Letters</i>, vol. 973, no. 1. IOP Publishing, 2024.","mla":"Mockler, Brenna, et al. “Tidal Disruption Events from Stripped Stars.” <i>Astrophysical Journal Letters</i>, vol. 973, no. 1, L9, IOP Publishing, 2024, doi:<a href=\"https://doi.org/10.3847/2041-8213/ad6c34\">10.3847/2041-8213/ad6c34</a>.","ista":"Mockler B, Gallegos-Garcia M, Götberg YLL, Miller JM, Ramirez-Ruiz E. 2024. Tidal disruption events from stripped stars. Astrophysical Journal Letters. 973(1), L9.","apa":"Mockler, B., Gallegos-Garcia, M., Götberg, Y. L. L., Miller, J. M., &#38; Ramirez-Ruiz, E. (2024). Tidal disruption events from stripped stars. <i>Astrophysical Journal Letters</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/2041-8213/ad6c34\">https://doi.org/10.3847/2041-8213/ad6c34</a>","chicago":"Mockler, Brenna, Monica Gallegos-Garcia, Ylva Louise Linsdotter Götberg, Jon M. Miller, and Enrico Ramirez-Ruiz. “Tidal Disruption Events from Stripped Stars.” <i>Astrophysical Journal Letters</i>. IOP Publishing, 2024. <a href=\"https://doi.org/10.3847/2041-8213/ad6c34\">https://doi.org/10.3847/2041-8213/ad6c34</a>.","ama":"Mockler B, Gallegos-Garcia M, Götberg YLL, Miller JM, Ramirez-Ruiz E. Tidal disruption events from stripped stars. <i>Astrophysical Journal Letters</i>. 2024;973(1). doi:<a href=\"https://doi.org/10.3847/2041-8213/ad6c34\">10.3847/2041-8213/ad6c34</a>","short":"B. Mockler, M. Gallegos-Garcia, Y.L.L. Götberg, J.M. Miller, E. Ramirez-Ruiz, Astrophysical Journal Letters 973 (2024)."},"quality_controlled":"1","ddc":["520"],"day":"12","type":"journal_article","scopus_import":"1","isi":1,"language":[{"iso":"eng"}],"date_published":"2024-09-12T00:00:00Z","issue":"1","publisher":"IOP Publishing","publication_status":"published","acknowledgement":"This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-2210452. We thank the participants and organizers of the summer Aspen 2023 workshop on “Stellar Interactions and the Transients They Cause” for fruitful discussions. B.M. is grateful for support from the Carnegie Theoretical Astrophysics\r\nCenter. M.G.-G. is grateful for the support from Northwestern University’s Presidential Fellowship. E.R.-R. thanks the Heising-Simons Foundation, NSF (AST-2150255 and AST2307710), Swift (80NSSC21K1409, 80NSSC19K1391), and Chandra (22-0142) for support. ","status":"public","date_created":"2024-09-22T22:01:42Z","author":[{"full_name":"Mockler, Brenna","first_name":"Brenna","last_name":"Mockler"},{"last_name":"Gallegos-Garcia","full_name":"Gallegos-Garcia, Monica","first_name":"Monica"},{"orcid":"0000-0002-6960-6911","full_name":"Götberg, Ylva Louise Linsdotter","first_name":"Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"last_name":"Miller","first_name":"Jon M.","full_name":"Miller, Jon M."},{"full_name":"Ramirez-Ruiz, Enrico","first_name":"Enrico","last_name":"Ramirez-Ruiz"}],"year":"2024","title":"Tidal disruption events from stripped stars","article_processing_charge":"Yes","oa_version":"Published Version"},{"volume":690,"publication":"Astronomy and Astrophysics","department":[{"_id":"YlGo"}],"file":[{"checksum":"b378b36726591f3479a927d924ab8e77","creator":"dernst","date_created":"2024-11-04T09:52:26Z","success":1,"file_size":4267349,"content_type":"application/pdf","file_id":"18500","date_updated":"2024-11-04T09:52:26Z","access_level":"open_access","relation":"main_file","file_name":"2024_AstronomyAstrophysics_Shenar.pdf"}],"abstract":[{"text":"Surveys in the Milky Way and Large Magellanic Cloud have revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary properties of massive stars at low metallicity, and therefore in conditions approaching those of the Early Universe, remain sparse. We present the Binarity at LOw Metallicity (BLOeM) campaign, an ESO large programme designed to obtain 25 epochs of spectroscopy for 929 massive stars in the Small Magellanic Cloud, allowing us to probe multiplicity in the lowest-metallicity conditions to date (Z = 0.2 Z⊙). BLOeM will provide (i) the binary fraction, (ii) the orbital configurations of systems with periods of P ≲ 3 yr, (iii) dormant black-hole binary candidates (OB+BH), and (iv) a legacy database of physical parameters of massive stars at low metallicity. Main sequence (OB-type) and evolved (OBAF-type) massive stars are observed with the LR02 setup of the GIRAFFE instrument of the Very Large Telescope (3960–4570 Å resolving power R = 6200; typical signal-to-noise ratio(S/N) ≈70–100). This paper utilises the first nine epochs obtained over a three-month time period. We describe the survey and data reduction, perform a spectral classification of the stacked spectra, and construct a Hertzsprung-Russell diagram of the sample via spectral-type and photometric calibrations. Our detailed classification reveals that the sample covers spectral types from O4 to F5, spanning the effective temperature and luminosity ranges 6.5 ≲ Teff/kK ≲ 45 and 3.7 < log L/L⊙ < 6.1 and initial masses of 8 ≲ Mini ≲ 80 M⊙. The sample comprises 159 O-type stars, 331 early B-type (B0–3) dwarfs and giants (luminosity classes V–III), 303 early B-type supergiants (II–I), and 136 late-type BAF supergiants. At least 82 stars are OBe stars: 20 O-type and 62 B-type (13% and 11% of the respective samples). In addition, the sample includes 4 high-mass X-ray binaries, 3 stars resembling luminous blue variables, 2 bloated stripped-star candidates, 2 candidate magnetic stars, and 74 eclipsing binaries.","lang":"eng"}],"_id":"18492","intvolume":"       690","article_type":"original","month":"10","oa":1,"date_updated":"2025-09-08T14:31:11Z","external_id":{"isi":["001336770600014"],"arxiv":["2407.14593"]},"publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"has_accepted_license":"1","doi":"10.1051/0004-6361/202451586","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"OA_type":"hybrid","quality_controlled":"1","article_number":"A289","file_date_updated":"2024-11-04T09:52:26Z","citation":{"ama":"Shenar T, Bodensteiner J, Sana H, et al. Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC. <i>Astronomy and Astrophysics</i>. 2024;690. doi:<a href=\"https://doi.org/10.1051/0004-6361/202451586\">10.1051/0004-6361/202451586</a>","short":"T. Shenar, J. Bodensteiner, H. Sana, P.A. Crowther, D.J. Lennon, M. Abdul-Masih, L.A. Almeida, F. Backs, S.R. Berlanas, M. Bernini-Peron, J.M. Bestenlehner, D.M. Bowman, V.A. Bronner, N. Britavskiy, A. De Koter, S.E. De Mink, K. Deshmukh, C.J. Evans, M. Fabry, M. Gieles, A. Gilkis, G. González-Torà, G. Gräfener, Y.L.L. Götberg, C. Hawcroft, V. Hénault-Brunet, A. Herrero, G. Holgado, S. Janssens, C. Johnston, J. Josiek, S. Justham, V.M. Kalari, Z.Z. Katabi, Z. Keszthelyi, J. Klencki, J. Kubát, B. Kubátová, N. Langer, R.R. Lefever, B. Ludwig, J. Mackey, L. Mahy, J. Maíz Apellániz, I. Mandel, G. Maravelias, P. Marchant, A. Menon, F. Najarro, L.M. Oskinova, A.J.G. O’Grady, R. Ovadia, L.R. Patrick, D. Pauli, M. Pawlak, V. Ramachandran, M. Renzo, D.F. Rocha, A.A.C. Sander, T. Sayada, F.R.N. Schneider, A. Schootemeijer, E.C. Schösser, C. Schürmann, K. Sen, S. Shahaf, S. Simón-Díaz, M. Stoop, S. Toonen, F. Tramper, J.T. Van Loon, R. Valli, L.A.C. Van Son, A. Vigna-Gómez, J.I. Villaseñor, J.S. Vink, C. Wang, R. Willcox, Astronomy and Astrophysics 690 (2024).","ieee":"T. Shenar <i>et al.</i>, “Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC,” <i>Astronomy and Astrophysics</i>, vol. 690. EDP Sciences, 2024.","chicago":"Shenar, T., J. Bodensteiner, H. Sana, P. A. Crowther, D. J. Lennon, M. Abdul-Masih, L. A. Almeida, et al. “Binarity at LOw Metallicity (BLOeM): A Spectroscopic VLT Monitoring Survey of Massive Stars in the SMC.” <i>Astronomy and Astrophysics</i>. EDP Sciences, 2024. <a href=\"https://doi.org/10.1051/0004-6361/202451586\">https://doi.org/10.1051/0004-6361/202451586</a>.","ista":"Shenar T, Bodensteiner J, Sana H, Crowther PA, Lennon DJ, Abdul-Masih M, Almeida LA, Backs F, Berlanas SR, Bernini-Peron M, Bestenlehner JM, Bowman DM, Bronner VA, Britavskiy N, De Koter A, De Mink SE, Deshmukh K, Evans CJ, Fabry M, Gieles M, Gilkis A, González-Torà G, Gräfener G, Götberg YLL, Hawcroft C, Hénault-Brunet V, Herrero A, Holgado G, Janssens S, Johnston C, Josiek J, Justham S, Kalari VM, Katabi ZZ, Keszthelyi Z, Klencki J, Kubát J, Kubátová B, Langer N, Lefever RR, Ludwig B, Mackey J, Mahy L, Maíz Apellániz J, Mandel I, Maravelias G, Marchant P, Menon A, Najarro F, Oskinova LM, O’Grady AJG, Ovadia R, Patrick LR, Pauli D, Pawlak M, Ramachandran V, Renzo M, Rocha DF, Sander AAC, Sayada T, Schneider FRN, Schootemeijer A, Schösser EC, Schürmann C, Sen K, Shahaf S, Simón-Díaz S, Stoop M, Toonen S, Tramper F, Van Loon JT, Valli R, Van Son LAC, Vigna-Gómez A, Villaseñor JI, Vink JS, Wang C, Willcox R. 2024. Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC. Astronomy and Astrophysics. 690, A289.","apa":"Shenar, T., Bodensteiner, J., Sana, H., Crowther, P. A., Lennon, D. J., Abdul-Masih, M., … Willcox, R. (2024). Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC. <i>Astronomy and Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202451586\">https://doi.org/10.1051/0004-6361/202451586</a>","mla":"Shenar, T., et al. “Binarity at LOw Metallicity (BLOeM): A Spectroscopic VLT Monitoring Survey of Massive Stars in the SMC.” <i>Astronomy and Astrophysics</i>, vol. 690, A289, EDP Sciences, 2024, doi:<a href=\"https://doi.org/10.1051/0004-6361/202451586\">10.1051/0004-6361/202451586</a>."},"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","isi":1,"language":[{"iso":"eng"}],"scopus_import":"1","ddc":["520"],"day":"01","type":"journal_article","date_published":"2024-10-01T00:00:00Z","acknowledgement":"The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement numbers 772225: MULTIPLES). PAC and JMB are supported by the Science and Technology Facilities Council research grant ST/V000853/1 (PI. V. Dhillon). DMB gratefully acknowledges support from UK Research and Innovation (UKRI) in the form of a Frontier Research grant under the UK government’s ERC Horizon Europe funding guarantee (SYMPHONY; PI Bowman; grant number: EP/Y031059/1), and a Royal Society University Research Fellowship (PI Bowman; grant number: URF\\R1\\231631). ZK acknowledges support from JSPS Kakenhi Grant-in-Aid for Scientific Research (23K19071). IM acknowledges support from the Australian Research Council (ARC) Centre of Excellence for Gravitational Wave Discovery (OzGrav), through project number CE230100016. AACS, VR, RRL, and MBP are funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) in the form of an Emmy Noether Research Group – Project-ID 445674056 (SA4064/1-1, PI Sander). GGT and JJ are supported by the German Deutsche Forschungsgemeinschaft (DFG) under Project-ID 496854903 (SA4064/2-1, PI Sander) VR, GGT, and AACS further acknowledge support from the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. ECS acknowledges financial support by the Federal Ministry for Economic Affairs and Climate Action (BMWK) via the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR) grant 50 OR 2306 (PI: Ramachandran/Sander). This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 945806) and is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC 2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). LMO is thankful for the funding provided by the DFG grant 443790621. This paper benefited from discussions at the International Space Science Institute (ISSI) in Bern through ISSI International Team project 512 (Multiwavelength View on Massive Stars in the Era of Multimessenger Astronomy). DP acknowledges financial support by the Deutsches Zentrum für Luft und Raumfahrt (DLR) grant FKZ 50OR2005. JIV acknowledges the European Research Council for support from the ERC Advanced grant ERC-2021-ADG101054731. JSV is supported by STFC (Science and Technology Facilities Council) funding under grant number ST/V000233/1. GH, SS-D, SRB and AH acknowledge support from the State Research Agency (AEI) of the Spanish Ministry of Science and Innovation (MICIN) and the European Regional Development Fund, FEDER under grants PID2021-122397NB-C21 and CEX2019-000920-S. SRB also acknowledges financial support by NextGeneration EU/PRTR and MIU (UNI/551/2021) through grant Margarita Salas-ULL. DFR is thankful for the support of the CAPES-Br and FAPERJ/DSC-10 (SEI-260003/001630/2023). F.N., and L.R.P. acknowledge support by grants PID2019-105552RB-C41 and PID2022-137779OB-C41 funded by MCIN/AEI/10.13039/501100011033 by “ERDF A way of making Europe”. MG acknowledges financial support from the grants PID2021-125485NB-C22, CEX2019-000918-M funded by MCIN/AEI/10.13039/501100011033 (State Agency for Research of the Spanish Ministry of Science and Innovation) and SGR-2021-01069 (AGAUR). GM acknowledges funding support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 772086). JMA acknowledges support from the Spanish Government Ministerio de Ciencia e Innovación and Agencia Estatal de Investigación (10.13 039/501 100 011 033) through grant PID2022-136640 NB-C22 and from the Consejo Superior de Investigaciones Científicas (CSIC) through grant 2022-AEP 005. MP is supported by the BEKKER fellowship BPN/BEK/2022/1/00106 from the Polish National Agency for Academic Exchange. KS is funded by the National Science Center (NCN), Poland, under grant number OPUS 2021/41/B/ST9/00757. JM acknowledges support from a Royal Society-Science Foundation Ireland University Research Fellowship. SJ acknowledges support from the FWO PhD fellowship under project 11E1721N. FB acknowledges the support of the European Research Council (ERC) Horizon Europe under grant agreement number 101044048.","date_created":"2024-11-03T23:01:44Z","status":"public","publication_status":"published","publisher":"EDP Sciences","arxiv":1,"article_processing_charge":"Yes (in subscription journal)","title":"Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC","oa_version":"Published Version","author":[{"first_name":"T.","full_name":"Shenar, T.","last_name":"Shenar"},{"first_name":"J.","full_name":"Bodensteiner, J.","last_name":"Bodensteiner"},{"last_name":"Sana","full_name":"Sana, H.","first_name":"H."},{"full_name":"Crowther, P. A.","first_name":"P. A.","last_name":"Crowther"},{"full_name":"Lennon, D. J.","first_name":"D. J.","last_name":"Lennon"},{"first_name":"M.","full_name":"Abdul-Masih, M.","last_name":"Abdul-Masih"},{"first_name":"L. A.","full_name":"Almeida, L. A.","last_name":"Almeida"},{"last_name":"Backs","full_name":"Backs, F.","first_name":"F."},{"last_name":"Berlanas","first_name":"S. R.","full_name":"Berlanas, S. R."},{"full_name":"Bernini-Peron, M.","first_name":"M.","last_name":"Bernini-Peron"},{"last_name":"Bestenlehner","full_name":"Bestenlehner, J. M.","first_name":"J. M."},{"last_name":"Bowman","first_name":"D. M.","full_name":"Bowman, D. M."},{"first_name":"V. A.","full_name":"Bronner, V. A.","last_name":"Bronner"},{"last_name":"Britavskiy","first_name":"N.","full_name":"Britavskiy, N."},{"full_name":"De Koter, A.","first_name":"A.","last_name":"De Koter"},{"last_name":"De Mink","first_name":"S. E.","full_name":"De Mink, S. E."},{"last_name":"Deshmukh","full_name":"Deshmukh, K.","first_name":"K."},{"last_name":"Evans","first_name":"C. J.","full_name":"Evans, C. J."},{"full_name":"Fabry, M.","first_name":"M.","last_name":"Fabry"},{"first_name":"M.","full_name":"Gieles, M.","last_name":"Gieles"},{"first_name":"A.","full_name":"Gilkis, A.","last_name":"Gilkis"},{"last_name":"González-Torà","full_name":"González-Torà, G.","first_name":"G."},{"first_name":"G.","full_name":"Gräfener, G.","last_name":"Gräfener"},{"full_name":"Götberg, Ylva Louise Linsdotter","first_name":"Ylva Louise Linsdotter","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","orcid":"0000-0002-6960-6911"},{"last_name":"Hawcroft","full_name":"Hawcroft, C.","first_name":"C."},{"full_name":"Hénault-Brunet, V.","first_name":"V.","last_name":"Hénault-Brunet"},{"first_name":"A.","full_name":"Herrero, A.","last_name":"Herrero"},{"last_name":"Holgado","first_name":"G.","full_name":"Holgado, G."},{"first_name":"S.","full_name":"Janssens, S.","last_name":"Janssens"},{"first_name":"C.","full_name":"Johnston, C.","last_name":"Johnston"},{"first_name":"J.","full_name":"Josiek, J.","last_name":"Josiek"},{"full_name":"Justham, S.","first_name":"S.","last_name":"Justham"},{"last_name":"Kalari","first_name":"V. M.","full_name":"Kalari, V. M."},{"last_name":"Katabi","first_name":"Z. Z.","full_name":"Katabi, Z. Z."},{"first_name":"Z.","full_name":"Keszthelyi, Z.","last_name":"Keszthelyi"},{"last_name":"Klencki","first_name":"J.","full_name":"Klencki, J."},{"last_name":"Kubát","first_name":"J.","full_name":"Kubát, J."},{"last_name":"Kubátová","full_name":"Kubátová, B.","first_name":"B."},{"first_name":"N.","full_name":"Langer, N.","last_name":"Langer"},{"last_name":"Lefever","first_name":"R. R.","full_name":"Lefever, R. R."},{"full_name":"Ludwig, B.","first_name":"B.","last_name":"Ludwig"},{"first_name":"J.","full_name":"Mackey, J.","last_name":"Mackey"},{"last_name":"Mahy","full_name":"Mahy, L.","first_name":"L."},{"last_name":"Maíz Apellániz","first_name":"J.","full_name":"Maíz Apellániz, J."},{"last_name":"Mandel","full_name":"Mandel, I.","first_name":"I."},{"last_name":"Maravelias","full_name":"Maravelias, G.","first_name":"G."},{"last_name":"Marchant","full_name":"Marchant, P.","first_name":"P."},{"last_name":"Menon","first_name":"A.","full_name":"Menon, A."},{"first_name":"F.","full_name":"Najarro, F.","last_name":"Najarro"},{"last_name":"Oskinova","first_name":"L. M.","full_name":"Oskinova, L. M."},{"last_name":"O'Grady","full_name":"O'Grady, A. J.G.","first_name":"A. J.G."},{"first_name":"R.","full_name":"Ovadia, R.","last_name":"Ovadia"},{"last_name":"Patrick","full_name":"Patrick, L. R.","first_name":"L. R."},{"last_name":"Pauli","first_name":"D.","full_name":"Pauli, D."},{"full_name":"Pawlak, M.","first_name":"M.","last_name":"Pawlak"},{"last_name":"Ramachandran","first_name":"V.","full_name":"Ramachandran, V."},{"last_name":"Renzo","first_name":"M.","full_name":"Renzo, M."},{"last_name":"Rocha","first_name":"D. F.","full_name":"Rocha, D. F."},{"full_name":"Sander, A. A.C.","first_name":"A. A.C.","last_name":"Sander"},{"last_name":"Sayada","full_name":"Sayada, T.","first_name":"T."},{"last_name":"Schneider","full_name":"Schneider, F. R.N.","first_name":"F. R.N."},{"full_name":"Schootemeijer, A.","first_name":"A.","last_name":"Schootemeijer"},{"last_name":"Schösser","full_name":"Schösser, E. C.","first_name":"E. C."},{"first_name":"C.","full_name":"Schürmann, C.","last_name":"Schürmann"},{"first_name":"K.","full_name":"Sen, K.","last_name":"Sen"},{"full_name":"Shahaf, S.","first_name":"S.","last_name":"Shahaf"},{"full_name":"Simón-Díaz, S.","first_name":"S.","last_name":"Simón-Díaz"},{"last_name":"Stoop","full_name":"Stoop, M.","first_name":"M."},{"first_name":"S.","full_name":"Toonen, S.","last_name":"Toonen"},{"first_name":"F.","full_name":"Tramper, F.","last_name":"Tramper"},{"last_name":"Van Loon","full_name":"Van Loon, J. Th","first_name":"J. Th"},{"first_name":"R.","full_name":"Valli, R.","last_name":"Valli"},{"last_name":"Van Son","full_name":"Van Son, L. A.C.","first_name":"L. A.C."},{"last_name":"Vigna-Gómez","full_name":"Vigna-Gómez, A.","first_name":"A."},{"last_name":"Villaseñor","first_name":"J. I.","full_name":"Villaseñor, J. I."},{"full_name":"Vink, J. S.","first_name":"J. S.","last_name":"Vink"},{"last_name":"Wang","full_name":"Wang, C.","first_name":"C."},{"last_name":"Willcox","first_name":"R.","full_name":"Willcox, R."}],"year":"2024","OA_place":"publisher"},{"_id":"18524","abstract":[{"text":"Recent works have constrained the binary fraction of evolved populations of massive stars in local galaxies such as red supergiants and Wolf–Rayet stars, but the binary fraction of yellow supergiants (YSGs) in the Hertzsprung gap remains unconstrained. Binary evolution theory predicts that the Hertzsprung gap is home to multiple populations of binary systems with varied evolutionary histories. In this paper, we develop a method to distinguish single YSGs from YSG plus O- or B-type main-sequence binaries using optical and ultraviolet photometry, and then apply this method to identify candidate YSG binaries in the Magellanic Clouds. After constructing a set of combined stellar atmosphere models, we find that optical photometry is, given typical measurement and reddening uncertainties, sufficient to discern single YSGs from YSG+OB binaries if the OB-star is at least ∼5M⊙ for Teff,YSG ∼ 4000 K, but requires a ∼20M⊙ OB star for YSGs up to Teff,YSG ∼ 9000 K. For these hotter YSG temperatures, ultraviolet photometry allows binaries with OB companions as small as ∼7M⊙ to be identified. We use color–color spaces developed from these models to search for evidence of excess blue or ultraviolet light in a set of ∼1000 YSG candidates in the Magellanic Clouds. We identify hundreds of candidate YSG binary systems and report a preliminary fraction of YSGs that show a blue/UV color excess of 20%–60%. Spectroscopic follow-up is now required to confirm the true nature of this population.","lang":"eng"}],"intvolume":"       975","file":[{"access_level":"open_access","date_updated":"2024-11-11T09:20:45Z","relation":"main_file","file_name":"2024_AstrophysicalJour_Grady.pdf","checksum":"0e9bb88b5048ecc782ac27953c84b8ce","creator":"dernst","content_type":"application/pdf","date_created":"2024-11-11T09:20:45Z","success":1,"file_size":34634395,"file_id":"18535"}],"month":"11","article_type":"original","volume":975,"DOAJ_listed":"1","department":[{"_id":"YlGo"}],"publication":"Astrophysical Journal","external_id":{"isi":["001339486900001"],"arxiv":["2406.17177"]},"date_updated":"2025-09-08T14:37:18Z","oa":1,"doi":"10.3847/1538-4357/ad778a","has_accepted_license":"1","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"citation":{"short":"A.J.G. O’Grady, M.R. Drout, K.F. Neugent, B. Ludwig, Y.L.L. Götberg, B.M. Gaensler, Astrophysical Journal 975 (2024).","ama":"O’Grady AJG, Drout MR, Neugent KF, Ludwig B, Götberg YLL, Gaensler BM. Binary yellow supergiants in the Magellanic Clouds. I. Photometric candidate identification. <i>Astrophysical Journal</i>. 2024;975. doi:<a href=\"https://doi.org/10.3847/1538-4357/ad778a\">10.3847/1538-4357/ad778a</a>","chicago":"O’Grady, Anna J.G., Maria R. Drout, Kathryn F. Neugent, Bethany Ludwig, Ylva Louise Linsdotter Götberg, and B. M. Gaensler. “Binary Yellow Supergiants in the Magellanic Clouds. I. Photometric Candidate Identification.” <i>Astrophysical Journal</i>. IOP Publishing, 2024. <a href=\"https://doi.org/10.3847/1538-4357/ad778a\">https://doi.org/10.3847/1538-4357/ad778a</a>.","apa":"O’Grady, A. J. G., Drout, M. R., Neugent, K. F., Ludwig, B., Götberg, Y. L. L., &#38; Gaensler, B. M. (2024). Binary yellow supergiants in the Magellanic Clouds. I. Photometric candidate identification. <i>Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ad778a\">https://doi.org/10.3847/1538-4357/ad778a</a>","mla":"O’Grady, Anna J. G., et al. “Binary Yellow Supergiants in the Magellanic Clouds. I. Photometric Candidate Identification.” <i>Astrophysical Journal</i>, vol. 975, 29, IOP Publishing, 2024, doi:<a href=\"https://doi.org/10.3847/1538-4357/ad778a\">10.3847/1538-4357/ad778a</a>.","ista":"O’Grady AJG, Drout MR, Neugent KF, Ludwig B, Götberg YLL, Gaensler BM. 2024. Binary yellow supergiants in the Magellanic Clouds. I. Photometric candidate identification. Astrophysical Journal. 975, 29.","ieee":"A. J. G. O’Grady, M. R. Drout, K. F. Neugent, B. Ludwig, Y. L. L. Götberg, and B. M. Gaensler, “Binary yellow supergiants in the Magellanic Clouds. I. Photometric candidate identification,” <i>Astrophysical Journal</i>, vol. 975. IOP Publishing, 2024."},"file_date_updated":"2024-11-11T09:20:45Z","article_number":"29","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","OA_type":"gold","quality_controlled":"1","type":"journal_article","day":"01","ddc":["520"],"language":[{"iso":"eng"}],"isi":1,"scopus_import":"1","date_published":"2024-11-01T00:00:00Z","publication_status":"published","publisher":"IOP Publishing","date_created":"2024-11-10T23:01:59Z","status":"public","acknowledgement":"The authors thank Aaron Tohuvavohu, Katie Breivik, Marten van Kerkwijk, Jakub Klencki, Eva Laplace, and Dae-Sik Moon for helpful discussions, and Adiv Paradise for helpful edits. The authors also thank the anonymous reviewer for a helpful and constructive referee report.\r\nThe authors at the University of Toronto acknowledge that the land on which the University of Toronto operates is the traditional territory of the Huron–Wendat, the Seneca, and the Mississaugas of the Credit River. They are grateful to have the opportunity to work on this land.\r\nThe Dunlap Institute is funded through an endowment established by the David Dunlap family and the University of Toronto.\r\nA.J.G.O. is supported by a McWilliams Fellowship at Carnegie Mellon University. M.R.D. acknowledges support from the NSERC through grant RGPIN-2019-06186, the Canada Research Chairs Program, and the Dunlap Institute at the University of Toronto. B.M.G. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through grant RGPIN-2022-03163, and of the Canada Research Chairs program. Support for this work was provided by NASA through the NASA Hubble Fellowship Program grant Nos. HST-HF2-51457.001-A and HST-HF2-51516 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555.\r\nThis research has made use of the SIMBAD database (M. Wenger et al. 2000), operated at CDS, Strasbourg, France, and the SVO Filter Profile Service 13 supported by the Spanish MINECO through grant AYA2017-84089 (C. Rodrigo et al. 2012, 2020).\r\nThis research has made use of the following software: astropy (Astropy Collaboration et al. 2013, 2018, 2022), IRAF (D. Tody 1986, 1993), and TOPCAT (M. B. Taylor 2005).","year":"2024","author":[{"first_name":"Anna J.G.","full_name":"O’Grady, Anna J.G.","last_name":"O’Grady"},{"full_name":"Drout, Maria R.","first_name":"Maria R.","last_name":"Drout"},{"full_name":"Neugent, Kathryn F.","first_name":"Kathryn F.","last_name":"Neugent"},{"last_name":"Ludwig","first_name":"Bethany","full_name":"Ludwig, Bethany"},{"orcid":"0000-0002-6960-6911","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg","first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter"},{"last_name":"Gaensler","full_name":"Gaensler, B. M.","first_name":"B. M."}],"OA_place":"publisher","arxiv":1,"oa_version":"Published Version","article_processing_charge":"No","title":"Binary yellow supergiants in the Magellanic Clouds. I. Photometric candidate identification"}]