Stellar multiplicity is common amongst all stars, but becomes dominant especially for high masses.
Hence, massive stars tend to interact, exchange mass, exert tidal forces on each other and merge.
What are initial binary fractions?
What are their mass-ratio and period distributions?
How do stars interact?
What happens when they merge?
To study this, I combine multi-epoch spectroscopy and interferometry with techniques such as spectral disentangling and qunatitative spectroscopy.
Notable relevant publications:
Shenar et al. 2022, A&A, 665, 148: "Characterization of hidden companions in 51 single-lined spectroscopic binaries"
Shenar et al. 2020, A&A, 63: "The hidden companion in LB-1 unveiled by spectral disentangling"
Bodensteiner, Shenar et al. 2020, A&A, 641, 43: "Does HR 6819 contain a black hole? An alternative explanation"
Bodensteiner, Shenar & Sana 2020, A&A, 641, 42: "Investigating the lack of main sequence companions to Be stars"
Artist's impression of the binary interaction product HR 6819, originally thought to contain a black hole