A high-mass Planetary Nebula in a Galactic Open Cluster

TL;DR

This paper reports the discovery of a planetary nebula associated with a star cluster containing stars around five solar masses, providing evidence that higher-mass stars can form planetary nebulae, challenging previous assumptions.

Contribution

It presents the first confirmed case of a planetary nebula originating from a star with about five solar masses in a galactic open cluster.

Findings

Confirmed association through radial velocities and location within the cluster.

Supports theory that stars with 5+ solar masses can form planetary nebulae.

Provides insights into stellar evolution at higher mass ranges.

Abstract

Planetary Nebulae are the ionised ejected envelopes surrounding the remnant cores of dying stars. Theory predicts that main-sequence stars with one to about eight times the mass of our sun may eventually form planetary nebulae. Until now no example has been confirmed at the higher mass range. Here we report that planetary nebula BMP J1613-5406 is associated with Galactic star cluster NGC 6067. Stars evolving off the main sequence of this cluster have a mass around five solar masses. Confidence in the planetary nebula-cluster association comes from their tightly consistent radial velocities in a sightline with a steep velocity-distance gradient, common distances, reddening and location of the planetary nebula within the cluster boundary. This is an unprecedented example of a planetary nebular whose progenitor star mass is getting close to the theoretical lower limit of core-collapse supernova formation. It provides evidence supporting theoretical predictions that 5+ solar mass stars can form planetary nebulae. Further study should provide fresh insights into stellar and Galactic chemical evolution.