The Fast Rotating Star 51 Oph Probed by VEGA/CHARA

Stellar rotation is a key in our understanding of both mass-loss and evolution of intermediate and massive stars. It can lead to anisotropic mass-loss in the form of radiative wind or an excretion disk. We used the VEGA visible beam combiner installed on the CHARA array that reaches a sub milliarcsecond resolution. We derived, for […]

Circumstellar disks

Disks are very common structures found around stars of different masses and evolutionary status. In this chapter we will discuss the basic properties of disks and how interferometric observations can put constraints on their structure. The chapter is organized in three sections: geometry of disks, physical conditions and chemical composition, and kinematics.

SIMECA: a Code Dedicated to Active Hot Stars

Active hot stars are hot stars (Teff ≥ 8000 K) exhibiting emission lines (namely hydrogen lines) and IR excess which both originate in a circumstellar environment. In this paper we present in details the SIMECA (SImulation pour Etoiles Chaudes Actives) code which is the only code freely available to model the gaseous environment of active […]

Recent results from the SIMECA code and VLTI observations

We present recent results on active hot stars using the first VLTI/MIDI and VLTI/AMBER observations, and the SIMECA code developed by Stee (1994). α Arae was the first classical Be star observed with MIDI (June 2003) and AMBER (February 2005). The size of its circumstellar envelope was measured and thanks to the spectrally-resolved interferometric AMBER […]