Far ultraviolet spectrophotometry of BD +28 4211

Abstract

We report the results of a November 1989 rocket flight which recorded a flux calibrated spectrum of BD +28 4211 from 912 to 1150Å with 1Å resolution. BD +28 4211, an SdO type star, is commonly used as an ultraviolet calibration source in the IUE wavelength band. Our work extends the useful range of this standard shortward of Lyman α. Since previous experiments show marked disparity, this study will be useful in determining a standard in the 912 to 1216Å band.