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arXiv · 2508.20802

Looking for Signs of Unresolved Binarity in the Continuum of LAMOST Stellar Spectra

Mikhail Prokhorov·Kefeng Tan·Nikolay Samus·Ali Luo·Dana Kovaleva·Jingkun Zhao·Yujuan Liu·Pavel Kaygorodov·Oleg Malkov·Yihan Song·Sergey Sichevskij·Lev Yungelson·Gang Zhao
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Abstract

We describe an attempt to derive the binarity rate of samples of 166 A-, F-, G-, and K-type stars from LAMOST DR5 and 1000 randomly selected presumably single stars from Gaia DR3 catalogs. To this end, we compared continua of the observed spectra with the continua of synthetic spectra in the 3700 to 9097 Angstrom range. The latter spectra were reduced to the LAMOST set of wavelengths, while the former ones were smoothed. Next, we searched for every observed star the nearest synthetic spectrum using a four-parameter representation - effective temperature, gravity, [Fe/H], and a range of interstellar absorption values. However, rms deviations of observed spectra from synthetic ones appeared to be not sufficient to claim that any of the stars is a binary. We conclude that comparison of the intensity of pairs of spectral lines remains the best way to detect binarity.

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Mikhail Prokhorov, Kefeng Tan, Nikolay Samus, Ali Luo, Dana Kovaleva, Jingkun Zhao, Yujuan Liu, Pavel Kaygorodov, Oleg Malkov, Yihan Song, Sergey Sichevskij, Lev Yungelson, Gang Zhao. 2025-08-28. Looking for Signs of Unresolved Binarity in the Continuum of LAMOST Stellar Spectra. https://doi.org/10.3390/galaxies13040083

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