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arXiv · 2607.27395

Multiplicity of Massive Stars at Low Metallicity: Early Results from the BLOeM Campaign

T. Shenar·J. Bodensteiner·M. Abdul-Masih·F. Backs·S. R. Berlanas·J. M. Bestenlehner·A. Bobrick·D. M. Bowman·N. Britavskiy·P. A. Crowther·K. Deshmukh·M. Fabry·M. Gieles·A. Gilkis·G. González i Torà·G. Gräfener·M. Gull·Y. Götberg·C. Hawcroft·V. Hénault-Brunet·A. Herrero·G. Holgado·R. G. Izzard·S. Janssens·H. Jin·V. M. Kalari·Z. Katabi·A. de Koter·J. Klencki·B. Kubátová·J. Kubát·N. Langer·T. Lechien·D. Lennon·R. Lefever·B. Ludwig·L. Mahy·J. Maíz Apellániz·I. Mandel·A. Mang Román·G. Maravelias·P. Marchant·A. Menon·F. Najarro·A. O'Grady·L. Oskinova·R. Ovadia·L. R. Patrick·D. Pauli·M. Pawlak·M. Bernini Peron·A. Picco·V. Ramachandran·M. Renzo·D. F. Rocha·H. Sana·A. A. C. Sander·T. Sayada·A. Schootemeijer·F. R. N. Schneider·R. Seeburger·K. Sen·S. Shahaf·S. Simón-Díaz·M. Stoop·S. Toonen·F. Tramper·R. Valli·P. Van Daele·J. Th. van Loon·L. van Son·A. Vigna-Gómez·J. I. Villaseñor·J. S. Vink·C. Wang·X. -T. Xu
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Abstract

Massive stars at low metallicity (Z) play a central role in shaping the high-redshift Universe, yet their multiplicity remains poorly constrained. The Binarity at Low Metallicity (BLOeM) campaign is a two-year survey of 929 stars in the Small Magellanic Cloud with the Fibre Large Array Multi Element Spectrograph (FLAMES) instrument at ESO's Very Large Telescope, providing the first large-scale spectroscopic monitoring of massive stars at low Z (1/5 solar). Analysis of the initial nine epochs reveals high intrinsic binary fractions (>70%) on the main sequence and a steep decline in evolved objects. Analysis of the full dataset will yield orbital solutions, identify black-hole companions, and allow a derivation of the initial mass function for single and binary stars at low Z.

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T. Shenar, J. Bodensteiner, M. Abdul-Masih, F. Backs, S. R. Berlanas, J. M. Bestenlehner, A. Bobrick, D. M. Bowman, N. Britavskiy, P. A. Crowther, K. Deshmukh, M. Fabry, M. Gieles, A. Gilkis, G. González i Torà, G. Gräfener, M. Gull, Y. Götberg, C. Hawcroft, V. Hénault-Brunet, A. Herrero, G. Holgado, R. G. Izzard, S. Janssens, H. Jin, V. M. Kalari, Z. Katabi, A. de Koter, J. Klencki, B. Kubátová, J. Kubát, N. Langer, T. Lechien, D. Lennon, R. Lefever, B. Ludwig, L. Mahy, J. Maíz Apellániz, I. Mandel, A. Mang Román, G. Maravelias, P. Marchant, A. Menon, F. Najarro, A. O'Grady, L. Oskinova, R. Ovadia, L. R. Patrick, D. Pauli, M. Pawlak, M. Bernini Peron, A. Picco, V. Ramachandran, M. Renzo, D. F. Rocha, H. Sana, A. A. C. Sander, T. Sayada, A. Schootemeijer, F. R. N. Schneider, R. Seeburger, K. Sen, S. Shahaf, S. Simón-Díaz, M. Stoop, S. Toonen, F. Tramper, R. Valli, P. Van Daele, J. Th. van Loon, L. van Son, A. Vigna-Gómez, J. I. Villaseñor, J. S. Vink, C. Wang, X. -T. Xu. 2026-07-29. Multiplicity of Massive Stars at Low Metallicity: Early Results from the BLOeM Campaign. https://doi.org/10.18727/0722-6691%2F5417

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