Central Stars of Planetary Nebulae in Galactic Open Clusters: Providing additional data for the White Dwarf Initial-to-Final-Mass Relation

Abstract

The accurate (<10%) distances of Galactic star clusters, as defined from color-magnitude diagrams, allow precise determination of the physical parameters of any physically associated Planetary Nebula (PN) and also that of its central star (CSPN). Theoretical cluster isochrones can be used for the determination of the PN progenitor's mass and age, while photometry of its CSPN strongly constrains its intrinsic luminosity and mass given the known distance. The mass of the progenitor star can be related to the PN's chemical characteristics, determined from spectroscopic measurements and furthermore, provides additional data for the widely used white dwarf (WD) initial-to-final mass relation (IFMR). The IFMR is crucial for tracing the development of both carbon and nitrogen in entire galaxies. To date there is only one PN (PHR1315- 6555) confirmed to be physically associated with a Galactic Open Cluster (ESO 96 -SC04). This cluster has a turn-off mass ? 2.2 M?. Our deep HST photometry was used for the search of the CSPN of this unique PN and in this work, we present our results.