The Kinematical Structure of the Bipolar Nebulae M2–9 and M1–91

Both nebulae are of similar appearance consisting of a central core and two highly symmetrical, elongated lobes. Using the large vertical Coude spectrograph of the 2.2-m telescope on Calar Alto, Spain, we obtained long-slit spectra in the red of high spectral (12 km s−1 FWHM) and spatial (2″) resolution from various positions within the nebulae. Our data indicate high similarity in the kinematical structure of both nebulae. The central cores are dominated by very broad emission lines. The Hα profiles (width ≈ 1600 km s−1 at 5% level in M2-9) exhibit an absorption feature blue-shifted by ≈ 20 km s−1 relative to the emission maximum, similar to profiles observed in some Herbig-Be-stars.