Diffraction-limited bispectrum speckle interferometry and speckle polarimetry of the young bipolar outflow source S140IRS1

We present bispectrum speckle interferometry and speckle polarimetry of the deeply embedded infrared bipolar outflow source S140 IRS1, a massive proto stellar object in the L1204 molecular cloud. Using the SAO 6 m telescope, w e obtained 280 mas resolution polarization maps of S140 IRS1 as well as a K -band image with diffraction-limited resolution lambda/D of 76 mas, which i s the highest angular resolution image of a young outflow source ever obtai ned in the infrared. Our data suggest that the central source is marginally resolved with a FWHM diameter of approximately 20 mas (similar to 20 AU). The most remarkable feature in our image is a bright extended and very clum py structure pointing away from the central source in exactly the same dire ction as the blue-shifted CO outflow lobe. A centro-symmetric pattern of hi gh polarization in this feature suggests that we see scattered light from t he central source. We interprete this feature as the clumpy inner surface o f a partially evacuated cavity in the circumstellar envelope around IRS1, w hich has been excavated by the strong outflow from IRS1.