NIR interferometric observations of massive hierarchical triple systems: Tr16-104 and HD150136

We report on an observational astrometric study of the orbit of the tertiary stars in two massive hierarchical triple systems. The work is complemented by radial velocity data with the aim of deriving the full 3D orbit and constraints on the orbital planes. This is the first report of the tertiary star's detection for Tr16-104. The work is a natural extension of the search for binaries among massive O-stars. The basic motivation of the study of hierarchical triple systems is the determination of the masses of the individual components and the derivation of the relative orientation of the two orbital planes, with the ultimate aim of understanding the related star formation processes.