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arXiv · 2308.08584

Dynamical masses across the Hertzsprung-Russell diagram

Hsiang-Chih Hwang·Yuan-Sen Ting·Sihao Cheng·Joshua S. Speagle
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Abstract

We infer the dynamical masses of stars across the Hertzsprung-Russell (H-R) diagram using wide binaries from the Gaia survey. Gaia's high-precision astrometry measures the wide binaries' orbital motion, which contains the mass information. Using wide binaries as the training sample, we measure the mass of stars across the two-dimensional H-R diagram using the combination of statistical inference and neural networks. Our results provide the dynamical mass measurements for main-sequence stars from 0.1 to 2 M$_\odot$, unresolved binaries and unresolved triples on the main sequence, and the mean masses of giants and white dwarfs. Two regions in the H-R diagram show interesting behaviors in mass, where one of them is pre-main-sequence stars, and the other one may be related to close compact object companions like M dwarf-white dwarf binaries. These mass measurements depend solely on Newtonian dynamics, providing independent constraints on stellar evolutionary models and the occurrence rate of compact objects.

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Hsiang-Chih Hwang, Yuan-Sen Ting, Sihao Cheng, Joshua S. Speagle. 2023-08-16. Dynamical masses across the Hertzsprung-Russell diagram. https://doi.org/10.1093/mnras%2Fstae297

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