Ensemble Properties of the White Dwarf Population of the Old, Solar Metallicity Open Star Cluster Messier 67

Understand

White dwarfs are excellent forensic tools for studying end-of-life issues surrounding low- and intermediate-mass stars, and the old, solar-metallicity open star cluster Messier 67 is a proven laboratory for the study of stellar evolution for solar-type stars.

• In this paper, we present a detailed spectroscopic study of brighter (M_g < 12.4) white dwarfs in Messier 67, and, in combination with previously-published proper motion membership determinations, we identify a clean, representative sample of cluster white dwarfs, including 13 members with hydrogen-dominated atmospheres, at least one of which is a candidate double degenerate, and 5 members with helium-dominated atmospheres.
• Using this sample we test multiple predictions surrounding the final stages of stellar evolution in solar type stars.
• In particular, the stochasticity of the integrated mass lost by ~1.5 solar mass stars is less than 7% of the white dwarf remnant mass.