Modelling rapid rotators for stellar interferometry

Abstract

Optical long baseline interferometry is a powerful tool to study detailed stellar structures. In particular, rapid rotation induces interferometric signatures requiring a detailed modelling for correctly interpreting high angular resolution data. In the present paper we study the effects of uniform stellar rotation on interferometric observables using a physically coherent model that includes gravity darkening and geometrical deformation, as well as a radiation transfer code. We investigate the use of multibaseline and/or multi-channel observations, both in the continuum and spectral lines, in order to obtain the unique solutions for relevant model parameters. We show that this is possible and we provide a guide for observers in order to perform this task. However, this turns out to be quite demanding in terms of sensitivity requiring the use of new generation interferometers.