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arXiv · 2201.05146

Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster

A. Malofeeva·A. Seleznev·G. Carraro
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Abstract

The identification of binary stars of different mass ratios in resolved stellar populations is a challenging task. We show how the photometric diagram constructed with the pseudo-colors (H-W2)-W1 vs W2-(BP-K) can be employed to estimate the binary and multiple star ratios and the distribution of their component mass ratio $q$ effectively. As an application, we investigate the Pleiades star cluster in the range of primary component mass between 0.5 and 1.8 $M_{\odot}$. The binary star ratio is found to be between 0.54$\pm$0.11 and 0.70$\pm$0.14. On the other hand, the ratio of systems with multiplicity more than 2 is between 0.10$\pm$0.00 and 0.14$\pm$0.01. The distribution of the component mass ratio $q$ has been approximated by a power law with the exponent between -0.53$\pm$0.10 and -0.63$\pm$0.22. Below 0.5 $M_{\odot}$, we expect a large number of brown dwarfs among secondary components.

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A. Malofeeva, A. Seleznev, G. Carraro. 2022-01-13. Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster. https://doi.org/10.3847/1538-3881%2Fac47a3

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