The long period eccentric orbit of the particle accelerator HD167971 revealed by long baseline interferometry

Particle acceleration and non-thermal emission processes in colliding-wind massive binaries constitute key issues in massive stars physics. The investigation of such processes requires a good knowledge of their stellar, stellar wind and orbital parameters. In this short contribution, I will present the latest results related to the case of HD167971, a system recently resolved by the VLTI. The information on the separation and on the luminosity ratio derived from these observations will also be discussed in the context of the so-called 'standard scenario' for particle acceleration and non-thermal processes in massive stars.