8329( 3) - 08/10/99 08:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8329 Version: 3 Check-in Date: 18-Feb-1999 08:59:34 1.Proposal Title: Double Degenerates Among DAO White Dwarfs ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Matthew Burleigh University of Leicester CoI: Dr. Martin Barstow University of Leicester Y CoI: Dr. Jay Holberg University of Arizona N CoI: Dr. Rex Saffer Villanova University N ------------------------------------------------------------------------------------ 5. Abstract The evolution of DAO white dwarfs, which have hybrid spectra showing both hydrogen and helium lines, is not well understood. It appears that they may be a rather disparate collection of objects with a variety of different origins. For example, it was recently discovered that one of these stars (Feige 55) lies in a close double degenerate system, and must therefore have undergone mass transfer and common envelope evolution. We propose to obtain STIS/FUV spectra of two problematic DAOs, GD561 and PG 1210+533, to determine whether they are also the product of binary evolution. Circumstantial evidence exists to suggest that both stars possess unresolved degenerate companions. However, ground based observations to search for radial velocity variations have proved inconclusive, since the H Balmer lines in these hot stars (50, 000K15, more than sufficient to detect heavy element features and accurately measure their velocities. For GD561 (V=14.52, 59 minutes visibility per orbit) we calculate that a signal/noise of 18.1 at 1300Angstrom will be achieved on the first orbit. For PG 1210+533 (V=14.12, 53 minutes visibility per orbit) we calculate that a signal/noise of 22.1 at 1300Angstrom will be achieved on the first orbit. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8329( 3) - 08/10/99 08:16 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GD561 STAR, DA RA=23H 45M 02.50S +/- 0.3S, J2000 V = 14.52 DEC=+80D 57' 00.0" +/- 0.3", F(1250)=8.0+/-1.0e-13 PLATE-ID=00LO Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1983.85 0.0 0.0 0.0 2 PG1210+533 STAR, DA RA=12H 13M 24.64S +/- 0.3S, J2000 V = 14.12 DEC=+53D 03' 57.9" +/- 0.3", F(1250)=1.4+/-0.2e-12 PLATE-ID=00LK Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1984.17 0.0 0.0 0.0 8329( 3) - 08/10/99 08:16 - [ 4] Visit: 01 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 GD561 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 1.0 S ONBOARD ACQ FOR 12, 13 CD P ------------------------------------------------------------------------------------------------------------------------------------ 12 GD561 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2673 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 13 GD561 STIS/F ACCUM 0.2X0.2 E140M 1425 1 3271 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8329( 3) - 08/10/99 08:16 - [ 5] Visit: 02 Visit Priority: Visit Requirements: AFTER 1 BY 23H TO 25H On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 GD561 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 1.0 S ONBOARD ACQ FOR 22 CD P ------------------------------------------------------------------------------------------------------------------------------------ 22 GD561 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2673 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8329( 3) - 08/10/99 08:16 - [ 6] Visit: 03 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 PG1210+533 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S ONBOARD ACQ FOR 32, 33 CD P ------------------------------------------------------------------------------------------------------------------------------------ 32 PG1210+533 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2515 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 33 PG1210+533 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2996 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8329( 3) - 08/10/99 08:16 - [ 7] Visit: 04 Visit Priority: Visit Requirements: AFTER 3 BY 23H TO 25H On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 PG1210+533 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S ONBOARD ACQ FOR 42 CD P ------------------------------------------------------------------------------------------------------------------------------------ 42 PG1210+533 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2515 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8329( 3) - 08/10/99 08:16 - [ 8] Summary Form for Proposal 8329 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 12, 13 AFTER 1 BY 23H TO 25H ONBOARD ACQ FOR 22 ONBOARD ACQ FOR 32, 33 AFTER 3 BY 23H TO 25H ONBOARD ACQ FOR 42 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names GD561 PG1210+533 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------