UV (IUE) spectra of the central stars of high latitude planetary nebulae Hb7 and Sp3

We present an analysis of the UV (IUE) spectra of the central stars of Hb7 and Sp3. Comparison with the IUE spectrum of the standard star HD 93205 leads to a spectral classification of O3V for these stars, with an effective temperature of 50 000 K. From the P-Cygni profiles of CIV (1550 Å), we derive stellar wind velocities and mass loss rates of -1317 km s^-1 +/- 300 km s^-1 and 2.9*E^-8 M_sun yr^-1 and -1603 km s^-1 +/- 400 km s^-1 and 7*E^-9 M_sun yr^-1 for Hb7 and Sp3 respectively. From all the available data, we reconstruct the spectral energy distribution of Hb7 and Sp3. Based on the observations obtained with the International Ultraviolet Explorer (IUE), retrieved from the IUE Final Archive at VILSPA, Madrid, Spain.