The optical spectrum of hydrogen at 160-350 million gauss in the white dwarf GRW +70 8247.

Abstract

Spectra from the magnetic white dwarf Grw +70 deg 8247 are compared with Roesner et al's. (1984) hydrogen spectrum up to 10 to the 9th G. It is noted that nearly all definite absorption features coincide with transitions whose energy is stationary or nearly stationary, with field strength in the 1.6 to 3.5 X 10 to the 8th G range. The complex spectrum of circular polarization is generally consistent with dipolar field geometry. The surface field presently derived is not consistent with the interpretataion of the weak 1345 A feature in the IUE spectrum as being due to Lyman-alpha, which is presently suggested to be much stronger, causing a broad depression in the continuum below 1400 A.