2012A&A...545L..10W

We study the enigmatic B[e] star MWC300 to investigate its disk and binary with milli-arcsecond-scale angular resolution. We observed MWC300 with the VLTI/AMBER instrument in the H and K bands and compared these observations with temperature-gradient models to derive model parameters. The measured low visibility values, wavelength dependence of the visibilities, and wavelength dependence of the closure phase directly suggest that MWC300 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 (∼4.4mas or ∼7.9AU), the flux ratio of the binary components (∼2.2), the disk temperature power-law index, and other parameters.