Two white dwarfs with oxygen-rich atmospheres

TL;DR

This paper reports the discovery of two white dwarfs with oxygen-rich atmospheres, suggesting they originate from the most massive progenitors that bypass core-collapse supernovae, providing new observational insights into stellar evolution.

Contribution

It presents the first observational evidence of white dwarfs with oxygen-rich atmospheres, indicating a new evolutionary pathway for massive stars avoiding supernovae.

Findings

Detection of two oxygen-rich white dwarfs.

Implication of massive progenitors avoiding core-collapse.

Evidence supporting alternative stellar evolution channels.

Abstract

Stars with masses in the range 7-10Msun end their lives either as massive white dwarfs or weak type II supernovae, and there are only limited observational constraints of either channel. Here we report the detection of two white dwarfs with large photospheric oxygen abundances, implying that they are bare oxygen-neon cores and that they may have descended from the most massive progenitors that avoid core-collapse.