SIMBAD references

High resolution optical images have been obtained of IRAS 0937+1212 (the 'Frosty Leo' Nebula). The images were taken with the DAO/CFHT High Resolution Camera using broad-band V and I filters and with an intermediate-band H-alpha filter. The red filters, particularly H-alpha, show that the bipolar nebula is surrounded by a nearly spherical envelope of material ∼30" in diameter. The high resolution images allow a detailed study of changes in the nebular morphology with wavelength. The ansae remain stationary with wavelength, whereas the positions of the lobes and hte position angle of the disk change with wavelength from the optical to the near-infrared. These results suggest that the ejection process is colliminated by the disk, which has been precessing with time. The possibility that the Frosty Leo nebula is not a post-AGB star but a pre-main sequence object formed in isolation from interstellar clouds is discussed.