KPD 2146+4117 - The coolest DBA white dwarf

Abstract

When Wickramasinghe and Whelan (1977) discovered the first DBA white dwarf LDS 785A, the possibility was considered that this object represented an exotic oddity. The fact that Shipman et al. (1985) have discovered five additional objects of this type suggests that the DBA stars are in fact a real class of degenerate object. This paper is concerned with the DBA white dwarf KPD 2146+4117, which was observed spectroscopically in October 1982 on a 1.5-m telescope with an image-tube scanner. The spectrum, obtained with 13 A resolution, covered the 3900-6800 A range. It reveals prominent absorption lines of both hydrogen and He I. Methods of analysis are discussed.