Carbon Atmosphere Dwarfs...

Smashing White Dwarfs - Max Planck Institute

97% of stars, including the Sun, will end their stellar lives as white dwarf stars. White dwarf stars no longer undergo fusion in their cores, so they slowly cool off. This cooling rate, along with the present temperature of a white dwarf, can be used to determine the age when stars began to form in a region. Merging white dwarfs are believed to be the cause for type Ia supernovae, which are used as the basis for most of our cosmology.

There are a number of different types of white dwarfs, identified and classified based on spectral characteristics. These characteristics also give some clues as to the progenitors of white dwarfs. For example, “DA” refers to a white dwarf with hydrogen lines. DBs have helium lines. DCs have no obvious lines (the C stands for continuum). DQs have carbon lines. DZs have metal lines and no hydrogen or helium. Additionally, astronomers will add a V at the end if the white dwarf is pulsating. The paper today presents data on a new DQV, a variable, carbon atmosphere white dwarf.

•Title: Photometric Variability in a Warm, Strongly Magnetic DQ White Dwarf, SDSS J103655.39+652252.2
•Authors: Williams, K.A., Winget, D.E., Montgomery, M.H. et al.
•First Author Institution: Texas A&M University – Commerce

Astrobites: A New Pulsating, Magnetic, Carbon Atmosphere White Dwarf