Reconstruction and Analysis of Component Spectra of Binary and Multiple Stars

TL;DR

This paper reviews recent methods for reconstructing individual spectra of binary and multiple stars from composite spectra, enabling detailed chemical and evolutionary studies of stellar components previously inaccessible.

Contribution

It introduces new spectral separation techniques and applies them to analyze elemental abundances and test stellar evolution models including rotational mixing effects.

Findings

Successful spectral reconstruction of binary star components

Detection of elemental abundance variations in high-mass stars

Insights into stellar evolution models with rotational mixing

Abstract

In the last two decades about a dozen methods were invented which derive, from a series of composite spectra over the orbit, the spectra of individual components in binary and multiple systems. Reconstructed spectra can then be analyzed with the tools developed for single stars. Eventually this has created the opportunity for chemical composition studies in previously inaccessible components of binary stars, and to follow their chemical evolution, an important aspect in understanding evolution of stellar systems. First, we review new developments in techniques to separate and reconstruct individual spectra, and thereafter concentrate on some applications. In particular, we emphasize the elemental abundance studies for high-mass stars, and present our recent results in probing theoretical evolution models which include effects of rotationally induced mixing.