The distances of less-evolved planetary nebulae: a further test of statistical distance scales.

It has recently been pointed out that a number of the methods used to determine planetary nebulae (PNe) distances may be appreciably in error. Whilst the scales of , and others are appropriate for higher radio brightness temperatures TB, those of Phillips and Daub are more relevant where TB is small. We note, in the following, that the absolute bolometric magnitudes of less-evolved PNe are likely to be similar. The mean value of can therefore be used to constrain PNe distances D, and confirm the distance scales for higher TB outflows. We have used this procedure to evaluate distances to a further 47 PNe, and we find that the mean values of are consistent with those of , , Phillips et al. (2004) and . They are, as expected, inconsistent with the lower TB scale of . [ABSTRACT FROM AUTHOR]