Generality of the progenitor-mass comparison for weak-emission-line planetary nebulae

Determine whether the similarity between the progenitor masses inferred for the weak-emission-line planetary nebulae studied by Méndez et al. and those inferred for NGC 6572, NGC 6884, and M 1-71 using the post-asymptotic-giant-branch tracks of Miller Bertolami (2016) represents a general trend or merely a coincidence.

Background

The paper examines three Galactic planetary nebulae near the bright-end cutoff of the planetary nebula luminosity function: NGC 6572, NGC 6884, and M 1-71. Their central stars exhibit weak-emission-line-star features, but the study argues that some of the relevant emission lines originate in the nebula rather than the stars and that the central stars are more likely hydrogen-rich than hydrogen-poor.

The authors compare their inferred progenitor-mass range of approximately 1.30–1.75 solar masses with the 1.50–2.00 solar-mass range reported for a separate sample of weak-emission-line planetary nebulae. They note that differences in the adopted post-asymptotic-giant-branch evolutionary tracks may account for the apparent agreement, leaving unresolved whether the similarity reflects a population-wide relation or an accidental correspondence.