5817( 0) - 07/18/95 18:05 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5817 Version: ********** Check-in Date: ********** 1.Proposal Title: The UV energy distributions of white ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Hot Stars AR 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Saeqa Vrtilek University of Maryland CoI: Fuhua Cheng University of Maryland N CoI: Keith Horne University of Utrecht N CoI: Edward Sion Villanova University N CoI: Ivan Hubeny NASA N ------------------------------------------------------------------------------------ 6. Abstract We have generated a grid of UV energy distributions for white dwarfs in the temperature range between 10,000 to 60,000 K at different high gravities and chemical abundances. These synthetic spectra include the contribution from quasi- molecular interactions of H atoms with H and H^+, seen in all DA stars between 9,000K and 19,000K, and have been applied to WZ Sge and VW Hyi systems (Sion et al. 1994a,b). We have also developed a code to calculate the absorption by intervening disk material that has been successfully applied to the OY Car system (Horne et al. 1994). Our proposed research requests HST archives of DP Leo, we will use our models to determine the temperature, gravity, magnetic field and chemical abundance in the white dwarf photosphere. This has not been done by the original HST project. We will also extend previous work on U Gem and OY Car to study the evolution of white dwarf temperature and chemical abundance between outbursts., ------------------------------------------------------------------------------------ Observations Description ------------------------ Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 5817( 0) - 07/18/95 18:05 - [ 2] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5817( 0) - 07/18/95 18:05 - [ 3] Summary Form for Proposal 5817 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category AR ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Hot Stars ------------------------------------------------------------------------------------------------------------------------------------