Abstract

Invited Talk - Splinter MassiveStars

Thursday, 10 September 2026, 16:40   (MW-1050)

The physical properties of post-mass-transfer binaries

Rhys Seeburger 1, Hans-Walter Rix 2, Kareem El-Badry 2,3 , Johanna Müller-Horn 2, Alexander Dimoff 2, Jan Henneco 4, Jaime Villaseñor 2
1 Liverpool John Moores University, 2 MPIA, 3 California Institute of Technology, 4 Newcastle University

Post-mass-transfer binaries (PMTBs) have recently drawn attention in the context of the search for black hole binaries, and have aquired a reputation as black hole impostors. Most of the initially promising black hole binaries advocated in Gaia DR3 appear to be such PMTBs. But, of course, they are astrophysically interesting systems in their own right. Here we present disentangled spectra for a number of these systems drawing on multi epoch spectroscopy to characterize the state of both components. Spectral disentangling allows us to analyse the component spectra individually, determining relevant stellar parameters and placing tighter constraints than SED fits alone. This, in turn, provides a valuable benchmark for testing models of binary interaction, stellar rotation, and the outcomes of mass transfer, with implications for the formation of compact objects, Be stars, and other exotic stellar populations.