Letter to the Editor

Gas and dust in the inner disk of the Herbig Ae star MWC 758 ^*

¹ Osservatorio Astrofisico di Arcetri, INAF, Largo E. Fermi 5, 50125 Firenze, Italy
² California Institute of Technology, MC 105-24, 1200 East California Blvd., Pasadena CA 91125, USA e-mail: isella@astro.caltech.edu
³ Laboratoire d'Astrophysique de Grenoble, UMR 5571, Université Joseph Fourier/CNRS, BP 53, 38041 Grenoble Cedex 9, France
⁴ ESO, Karl-Schwarschild Strasse 2, 85748 Garching bei München, Germany

Received: 24 February 2008
Accepted: 25 March 2008

Abstract

We investigate the origin of the near-infrared emission of the Herbig Ae star MWC 758 on sub-astronomical unit (AU) scales using spectrally dispersed low resolution () AMBER/VLTI interferometric observations in the H (1.7 μm) and K (2.2 μm) bands. We find that the K band visibilities and closure phases are consistent with the presence of a dusty disk inner rim located at the dust evaporation distance (0.4 AU) while the bulk of the H band emission arises within 0.1 AU from the central star. Comparing the observational results with theoretical model predictions, we suggest that the H band emission is dominated by an hot gaseous accretion disk.