The Most Massive White Dwarfs in the Solar Neighborhood

Understand

We present an analysis of the most massive white dwarf candidates in the Montreal White Dwarf Database 100 pc sample.

• We identify 25 objects that would be more massive than $1.3~M_{\odot}$ if they had pure H atmospheres and CO cores, including two outliers with unusually high photometric mass estimates near the Chandrasekhar limit.
• We provide follow-up spectroscopy of these two white dwarfs and show that they are indeed significantly below this limit.
• We expand our model calculations for CO core white dwarfs up to $M=1.334\ M_\odot$, which corresponds to the high-density limit of our equation-of-state tables, $\rho = 10^9$ g cm$^{-3}$.