AMBER/VLTI observations of the B[e] star MWC 300^⋆

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
e-mail: ywang@mpifr.de
² Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109-1090, USA
³ Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402, USA
⁴ Université Joseph Fourier (UJF) – Grenoble 1 / CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France
⁵ Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, 06300 Nice, France
⁶ INAF – Osservatorio Astrofisico di Arcetri, Largo Fermi 5, 50125 Firenze, Italy

Received: 12 June 2012
Accepted: 3 August 2012

Abstract

Aims. We study the enigmatic B[e] star MWC 300 to investigate its disk and binary with milli-arcsecond-scale angular resolution.

Methods. We observed MWC 300 with the VLTI/AMBER instrument in the H and K bands and compared these observations with temperature-gradient models to derive model parameters.

Results. The measured low visibility values, wavelength dependence of the visibilities, and wavelength dependence of the closure phase directly suggest that MWC 300 consists of a resolved disk and a close binary. We present a model consisting of a binary and a temperature-gradient disk that is able to reproduce the visibilities, closure phases, and spectral energy distribution. This model allows us to constrain the projected binary separation (~4.4 mas or  ~7.9 AU), the flux ratio of the binary components (~2.2), the disk temperature power-law index, and other parameters.