EXTINCTION-DISTANCES TO PLANETARY-NEBULAE

Photometry in the Walraven VBLUW system is used to construct diagrams of color excess vs. distance for stars of spectral type earlier than A7 ( T-eff > 8000 K) within small fields around eight planetary nebulae. With these diagrams and the known interstellar reddening of the planetary nebulae distances or lower limits to the distances have been determined. For IC 2448 and TC 1 these reddening distances are considerably lower than those determined by Mendez et al. (1988a, 1992) with spectroscopic methods.