Planetary nebulae (PNe) can be used to trace old and intermediate-age stellar populations in galaxies and in the intracluster medium out to approximately 20 Mpc. Photometric and spectroscopic observations of PNe provide information about: 1) the stellar death rate, 2) the chemical composition of the planetaries' parent stars, 3) the distance to the galaxy, and 4) the stellar dynamics of the parent stellar population and the distribution of mass in the galaxy.
Planetary nebulae in the intracluster or intragroup medium (ICPNe) provide a measure of past tidal stripping and tidal disruption of galaxies within the cluster or group. Depending on the evolutionary state of the cluster, ICPNe may provide thousands of test particles that can be used to study the cluster's dynamics.