The planetary nebula Abell 39
This page describes how planetary nebulae can be used to derive accurate distances to galaxies up to 20 Mpc away. Planetary Nebulae have very repeatable luminosity distributions, and this uniformity is the key to the technique.
The luminosity function for planetary nebulae in the nearby Andromeda Galaxy (M31). Notice that the function drops to zero very sharply at the bright (left) end of the distribution. This signature provides an indicator of the distance to a sample of nebulae.
For more information about planetary nebula luminosity functions (PNLF), see the pages listed below:
Send comments to: firstname.lastname@example.org