DETERMINING HOT STAR WIND TERMINAL VELOCITIES FROM LOW-RESOLUTION IUEDATA

Empirical relations are provided which enable consistent determination s of wind terminal velocities for hot stars where only low-resolution IU E spectra are available. The calibrations are based on terminal vel ocities derived from the violet limit of 'black' absorption troughs se en in high-resolution IU E spectra of saturated wind lines of hot star s, and the corresponding wavelengths of the absorption minima and emis sion peaks in low-resolution spectra of C IV lambda 1550 and N V lambd a 1240 P Cygni profiles of the same stars. The relations may be applie d to low-resolution IU E data of extragalactic WR and OB stars, and th e nuclei of planetary nebulae.