SIMBAD references

A 2-dimensional cylindrically symmetric ionisation model of the planetary nebula NGC 2440 is presented. The gridsize with which the model has been calculated has been adapted to match the spatial resolution of monochromatic CCD-images obtained in several emission lines. The comparison between "real" images and "model" images yields an accurate simulation of the ionisation structure. From our models we also determined a consistent set of physical quantities of NGC 2440. Our resulting distance is 500pc, the central star temperature and luminosity are 125000K and 250L_☉ respectively.