Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud

• DOI: 10.48550/arxiv.2502.12239
• Publication Date: 2025-02-17
• Authors: 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. Götberg; G. Holgado; C. Johnston; Z. Keszthelyi; J. Klencki; N. Langer; Ilya Mandel; A. S. 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. Th. van Loon; J. S. Vink
• Keywords: Small Magellanic Cloud; Large Magellanic Cloud; Multiplicity (mathematics)

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 crucial role in the fate massive stars, investigating multiplicity among BSGs helps shed light on such objects. We aim to estimate fraction sample Small Magellanic Cloud within Binarity at LOw Metallicity (BLOeM) survey. In total, we selected 262 targets with spectral types B0-B3 luminosity classes I-II. This work is based spectroscopic data collected by GIRAFFE instrument, mounted Very Large Telescope, which gathered nine epochs over three months. Our analysis for each target includes individual peak-to-peak radial velocity measurements, an investigation line profile variability, periodogram search possible short- long-period binaries. By applying 20 km s$^{-1}$ threshold velocities above would consider star be binary, resulting observed our BSG 23 $\pm$ 3$\%$. addition, derived reliable orbital periods 41 binaries potential candidates, there 17 eclipsing binaries, including SB1 SB2 systems less than 10 days. reported significant drop later B2 effective temperatures 18 kK, could indicate end main sequence phase this temperature regime. found no metallicity dependence BSGs, compared existing surveys Galaxy Cloud.