High resolution far-ultraviolet spectra of the O-type subdwarf BD +28 ^ { \circ } 4211 were obtained with the Far Ultraviolet Spectroscopic Explorer to measure the interstellar deuterium , nitrogen , and oxygen abundances in this direction .
The interstellar D i transitions are analyzed down to Ly \iota at 920.7 Å .
The star was observed several times at different target offsets in the direction of spectral dispersion .
The aligned and coadded spectra have high signal-to-noise ratios ( S/N = 50 - 100 ) .
D i , N i , and O i transitions were analyzed with curve-of-growth and profile fitting techniques .
A model of interstellar molecular hydrogen on the line of sight was derived from H _ { 2 } lines in the FUSE spectra and used to help analyze some features where blending with H _ { 2 } was significant .
The H i column density was determined from high resolution HST /STIS spectra of Ly \alpha to be log N ( H i ) = 19.846 \pm 0.035 ~ { } ( 2 \sigma ) , which is higher than is typical for sight lines in the local ISM studied for D/H .
We found that D/H = ( 1.39 \pm 0.21 ) \times 10 ^ { \small - 5 } ~ { } ( 2 \sigma ) and O/H = ( 2.37 \pm 0.55 ) \times 10 ^ { \small - 4 } ~ { } ( 2 \sigma ) .
O/H toward BD +28 ^ { \circ } 4211 appears to be significantly below the mean O/H ratio for the ISM and the Local Bubble .