Determine how massive stars form and why they exhibit high multiplicity

Determine the formation pathways of massive stars (stellar masses ≳ 8 M⊙) and establish the physical origins of their high multiplicity, specifying the physical processes that assemble binary and higher-order systems during the early stages of star formation.

Background

The paper investigates the formation and migration of massive-star binaries within a high-resolution star-cluster simulation. Early in the introduction, the authors emphasize long-standing uncertainties surrounding the formation of massive stars and the prevalence of multiple systems. These uncertainties motivate their numerical exploration of assembly processes, fragmentation channels, and gas-driven migration.

Massive star formation occurs in dense, optically thick regions with rapid accretion and strong feedback, making direct observation and interpretation challenging. The authors place their study within this context to help illuminate how multiplicity arises and evolves dynamically, but they explicitly acknowledge that the fundamental questions of formation pathways and multiplicity origins remain unresolved.

References

Despite their astrophysical importance, the formation of massive stars and the origin of their high multiplicity remain open questions \citep[e.g.,][]{2002ApJ...569..846Y,2007ARA&A..45..481Z, 2014prpl.conf..149T}.

— Formation of massive multiple-star systems: early migration and mergers  (2601.06251 - Chon et al., 9 Jan 2026) in Section 1 (Introduction)

Massive stars ($M_\text{ZAMS}>$ 8\,$M_\odot$, $L\gtrsim$ 10$3\,$$L_\odot$) dominate the physical and chemical processes of the interstellar medium on a galactic scale \citep{Oey2009}, but the specific mechanism(s) of their formation have yet to be determined \cite[see reviews by][]{Tan2014, Motte2018, Beuther2025}.

— The ALMA EGO-10 Survey of Massive Protoclusters: Correlation of 1.3 mm Continuum Source Clustering with Evolutionary State  (2608.23527 - Logue et al., 24 Aug 2026) in Section 1, Introduction

The impact of such densely clustered environs on the massive star formation process has not yet been fully characterised.

— The ALMA EGO-10 Survey of Massive Protoclusters: Correlation of 1.3 mm Continuum Source Clustering with Evolutionary State  (2608.23527 - Logue et al., 24 Aug 2026) in Section 3.3, subsection “Clustered Massive Star Formation”

The mechanisms responsible for the formation of stellar clusters and associations, and by extension the origin of the initial mass function \citep[IMF;][]{Salpeter1955, Kroupa2026} of stars, remains one of the long-standing unsolved problems in the field of star formation \citep[e.g.,][]{Offner2014}.

— Star Formation across the Galaxy  (2610.21944 - Sanchez-Monge et al., 15 Oct 2026) in Section 2, subsection “Determining the initial stellar population: Fragmentation and multiplicity”