Resolving and probing the circumstellar disk of the herbig Ae star MWC 480 at λ=1.4 mm:: Evolved dust?

We present high-resolution 0."45 x 0."32 observations from the BIMA array toward the Herbig Ae system MWC 480 in the lambda = 1.4 mm dust continuum. We resolve a circumstellar disk of radius similar to 170 AU and constrain the disk parameters by comparing the observations to flat-disk models. These results show that the typical fit parameters of the disk, such as the mass, M-D similar to 0.04-0.18 M-circle dot, and the surface density power-law index, p = 0.5 or 1, are comparable to those of the lower mass T Tauri stars. The dust in the MWC 480 disk can be modeled as processed dust material (beta approximate to 0.8), similar to the Herbig Ae star CQ Tau disk; the fitted disk parameters are also consistent with less evolved dust (beta approximate to 1.2). The possibility of grain growth in the MWC 480 circumstellar disk is supported by the acceptable fits with beta approximate to 0.8. The surface density power-law profiles of p = 0.5 and p = 1 can be easily fitted to the MWC 480 disk; however, a surface density power-law profile similar to the minimum mass solar nebula model p = 1.5 is ruled out at an 80% confidence level.