The absorption near 1400 A in the spectra of additional DA white dwarfs.

Abstract

Ultraviolet spectroscopic observations of five white dwarfs having published spectral types of DA made with the International Ultraviolet Explorer (IUE) satellite are reported. The three coolest objects: GD279 (0148 + 46), W485A (1327 - 08), and G231 - 40 (2117 + 53) have easily detected absorptions near lambda 1400. Of the two remaining stars, PG0039 + 045 may not be a true DA and GD140 (1134 + 30) is apparently too hot to show any feature near lambda 1400. It is argued that the lambda 1400 feature is produced by the lambda 1420 photoionization edge of Ca II.