Hot White Dwarfs

TL;DR

This paper reviews the physical properties, classification, and evolution of hot white dwarfs, highlighting recent observational and theoretical advances across various subclasses, including newly identified types like Hot DQ white dwarfs.

Contribution

It provides a comprehensive review of hot white dwarf subclasses, their properties, and recent advances, including the discovery of a new class, Hot DQ white dwarfs.

Findings

Detailed classification of hot white dwarf spectra.

Summary of recent observational and theoretical progress.

Introduction of the new Hot DQ white dwarf class.

Abstract

The article covers the physical properties and evolution of single white dwarfs ranging in temperature from 20,000K to 200,000 and higher, the hottest know electron-degenerate stars. After discussing the classification of their spectra, the author reviews the known properties, parameters, evolutionary state, as well as persisting and new puzzles regarding all spectroscopic subclasses of hot white dwarfs: the hot DA white dwarfs, the DAO white dwarfs, the PG1159 degenerates, the DO white dwarfs, the DB white dwarfs, the DBA white dwarfs, and the Hot DQ white dwarfs (an entirely new class). The most recent observational and theoretical advances are brought to bear on the topic.