We obtained spectro-interferometric observations in the visible of β Lyrae and υ Sgr using the instrument VEGA of the CHARA interferometric array. For β Lyrae, the dispersed fringe visibilities and differential phases were obtained in spectral regions containing the Hα and HeI 6678 lines and the Hβ and HeI 4921 lines. Whereas the source is unresolved in the continuum, the source of the emission lines is resolved and the photocenter of the bulk of the Hα emission exhibits offsets correlated with the orbital phase. For υ Sgr, both the continuum and Hα sources are resolved, but no clear binary signal is detected. The differential phase shift across the line reveals that the bulk of the Hα emission is clearly offset from the primary.
@article{arxiv.1001.1920,
title = {Spectro-interferometric observations of interacting massive stars with VEGA/CHARA},
author = {Daniel Bonneau and Olivier Chesneau and Denis Mourard and Philippe Stee},
journal= {arXiv preprint arXiv:1001.1920},
year = {2010}
}