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Bibliographic Details
Main Author: Esser, Nicolas
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.20245
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author Esser, Nicolas
author_facet Esser, Nicolas
contents We study binary stars moving through a uniform dark matter background and experiencing dynamical friction. The centre-of-mass motion of the pairs is taken into account. We derive formulas and timescales for the secular evolution of the orbital parameters for both wide and close binaries. We apply these results to environments typical of dark matter dominated ultra-faint dwarf galaxies and show that some binaries undergo significant eccentricity oscillations, while their semi-major axes decrease more gradually. We consider a simple binary star population and find that dynamical friction, notably, can enhance the bias from unresolved binaries in velocity dispersion measurements. With future, more detailed theoretical studies and improving observational capabilities, binary stars may serve as a tool to probe the dark matter content of some of the faintest galaxies.
format Preprint
id arxiv_https___arxiv_org_abs_2602_20245
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Dynamical friction on binary stars in dark matter dominated environments
Esser, Nicolas
Astrophysics of Galaxies
We study binary stars moving through a uniform dark matter background and experiencing dynamical friction. The centre-of-mass motion of the pairs is taken into account. We derive formulas and timescales for the secular evolution of the orbital parameters for both wide and close binaries. We apply these results to environments typical of dark matter dominated ultra-faint dwarf galaxies and show that some binaries undergo significant eccentricity oscillations, while their semi-major axes decrease more gradually. We consider a simple binary star population and find that dynamical friction, notably, can enhance the bias from unresolved binaries in velocity dispersion measurements. With future, more detailed theoretical studies and improving observational capabilities, binary stars may serve as a tool to probe the dark matter content of some of the faintest galaxies.
title Dynamical friction on binary stars in dark matter dominated environments
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2602.20245