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arXiv · 2609.39907

Towards breaking the degeneracy between stellar ages and unresolved multiplicity

Friedrich Anders·Anna B. A. Queiroz·Sagar Malhotra·Cristina Chiappini·Arman Khalatyan
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Abstract

Stellar age is the central desirable parameter we need to disentangle different Galactic formation scenarios. Nevertheless, no stellar age dating method is completely model-independent. Even in the best-case scenarios, present-day stellar age estimates are only precise to $\sim7\%$ and accurate to $\sim10-15\%$. A main drawback of state-of-the-art stellar parameter inference codes like {\tt StarHorse} is that they do not take into account unresolved stellar multiplicity. Especially in the case of nearly equal-mass binaries or higher-order systems on the main sequence, properly taking into account unresolved multiplicity is imperative for the next generation of stellar surveys. Simulation-based inference (SBI) is a robust and flexible approach for dealing with complex models where traditional likelihood-based methods become unfeasible. Here we sketch how SBI can be used to obtain precise stellar ages, masses, binary mass ratios, and other stellar parameters from spectroscopic, photometric, and astrometric measurements.

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Friedrich Anders, Anna B. A. Queiroz, Sagar Malhotra, Cristina Chiappini, Arman Khalatyan. 2026-09-30. Towards breaking the degeneracy between stellar ages and unresolved multiplicity. https://arxiv.org/abs/2609.39907

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