The Masses and Galactic Distribution of Southern Planetary Nebulae

Photoelectric measurements of absolute emission-line fluxes of far-southern planetary nebulae have been made. Thirty objects in the Magellanic Clouds and 88 objects in the Galaxy were included. Faint unresolved (planetary) nebulae in the Clouds are excited by stars below the main sequence, whereas the stars in the more luminous, resolved (diffuse) nebulae lie on, or near the main sequence. The upper limit to the total H β emission of any Magellanic Cloud planetary is |$2.5\,\times\,{10}^{35}\,\text{erg}\,\text{s}^{-1}$| . A discussion of present and previous mass determinations leads to a best estimate for the total mass of a planetary shell of between one tenth and one quarter of a solar mass. Approximate distances to the galactic planetaries have been calculated. The peak in the number of planetaries towards galactic longitude |${l}^\text{II}\,=\,{330}^{^{\circ}}$| is caused to some extent by the large number of typical planetaries there, but main factor is low interstellar absorption in this direction.