---
OA_place: publisher
OA_type: diamond
_id: '19844'
abstract:
- lang: eng
  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."
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.'
article_number: A38
article_processing_charge: Yes
article_type: original
arxiv: 1
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
- first_name: P. A.
  full_name: Crowther, P. A.
  last_name: Crowther
- first_name: N.
  full_name: Langer, N.
  last_name: Langer
- first_name: D. J.
  full_name: Lennon, D. J.
  last_name: Lennon
- first_name: L.
  full_name: Mahy, L.
  last_name: Mahy
- first_name: L. R.
  full_name: Patrick, L. R.
  last_name: Patrick
- first_name: J. I.
  full_name: Villaseñor, J. I.
  last_name: Villaseñor
- first_name: M.
  full_name: Abdul-Masih, M.
  last_name: Abdul-Masih
- first_name: D. M.
  full_name: Bowman, D. M.
  last_name: Bowman
- first_name: A.
  full_name: De Koter, A.
  last_name: De Koter
- first_name: S. E.
  full_name: De Mink, S. E.
  last_name: De Mink
- first_name: K.
  full_name: Deshmukh, K.
  last_name: Deshmukh
- first_name: M.
  full_name: Fabry, M.
  last_name: Fabry
- first_name: A.
  full_name: Gilkis, A.
  last_name: Gilkis
- 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
- first_name: G.
  full_name: Holgado, G.
  last_name: Holgado
- first_name: R. G.
  full_name: Izzard, R. G.
  last_name: Izzard
- first_name: S.
  full_name: Janssens, S.
  last_name: Janssens
- first_name: V. M.
  full_name: Kalari, V. M.
  last_name: Kalari
- first_name: Z.
  full_name: Keszthelyi, Z.
  last_name: Keszthelyi
- first_name: J.
  full_name: Kubát, J.
  last_name: Kubát
- first_name: I.
  full_name: Mandel, I.
  last_name: Mandel
- first_name: G.
  full_name: Maravelias, G.
  last_name: Maravelias
- first_name: L. M.
  full_name: Oskinova, L. M.
  last_name: Oskinova
- first_name: D.
  full_name: Pauli, D.
  last_name: Pauli
- first_name: V.
  full_name: Ramachandran, V.
  last_name: Ramachandran
- first_name: D. F.
  full_name: Rocha, D. F.
  last_name: Rocha
- first_name: M.
  full_name: Renzo, M.
  last_name: Renzo
- first_name: A. A.C.
  full_name: Sander, A. A.C.
  last_name: Sander
- first_name: F. R.N.
  full_name: Schneider, F. R.N.
  last_name: Schneider
- first_name: A.
  full_name: Schootemeijer, A.
  last_name: Schootemeijer
- first_name: K.
  full_name: Sen, K.
  last_name: Sen
- first_name: M.
  full_name: Stoop, M.
  last_name: Stoop
- first_name: S.
  full_name: Toonen, S.
  last_name: Toonen
- first_name: J. T.
  full_name: Van Loon, J. T.
  last_name: Van Loon
- first_name: R.
  full_name: Valli, R.
  last_name: Valli
- first_name: A.
  full_name: Vigna-Gómez, A.
  last_name: Vigna-Gómez
- first_name: J. S.
  full_name: Vink, J. S.
  last_name: Vink
- first_name: C.
  full_name: Wang, C.
  last_name: Wang
- first_name: X. T.
  full_name: Xu, X. T.
  last_name: Xu
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>'
  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>'
  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>.'
  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.'
  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.'
  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>.'
  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).
date_created: 2025-06-15T22:01:30Z
date_published: 2025-06-01T00:00:00Z
date_updated: 2026-04-16T08:17:17Z
day: '01'
ddc:
- '520'
department:
- _id: YlGo
doi: 10.1051/0004-6361/202452623
external_id:
  arxiv:
  - '2502.02641'
  isi:
  - '001497903100011'
file:
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  creator: dernst
  date_created: 2025-06-23T07:54:57Z
  date_updated: 2025-06-23T07:54:57Z
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has_accepted_license: '1'
intvolume: '       698'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '06'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
  eissn:
  - 1432-0746
  issn:
  - 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Binarity at LOw Metallicity (BLOeM): Multiplicity properties of Oe and Be
  stars'
tmp:
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  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 698
year: '2025'
...