Effective Temperatures of White Dwarfs

Of all the fields of stellar astronomy, the study of white dwarfs has been most influenced by work done on proper motions. From proper motion studies, particularly by Luyten and Giclas in recent years, many white dwarf candidates have been found. These candidates have been studied intensively, particularly by Greenstein who has obtained spectra and Eggen who has measured magnitude and colors. As a result, many new white dwarfs have been discovered, and we now have many examples of most types of white dwarfs. It is, therefore, possible to study each group separately and to find relationships between the various types of white dwarfs.