8638( 4) - 09/08/00 17:51 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8638 Version: 4 Check-in Date: 21-Mar-2000 11:49:02 1.Proposal Title: Temperature scale and metal abundances of hot hydrogen-rich central stars of planetary nebulae ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Klaus Werner Universitat Tubingen, Institut fur Astronomie & Astrophysik CoI: DP Jochen L. Deetjen Universitaet Tuebingen, Institut fuer N Astronomie und Astrophysik CoI: Dr. Stefan Dreizler Universitaet Tuebingen, Institut fuer N Astronomie und Astrophysik CoI: Prof. Ulrich Heber Universitaet Erlangen-Nuernberg, N Sternwarte Bamberg CoI: DP Thorsten Nagel Universitaet Tuebingen, Institut fuer N Astronomie und Astrophysik CoI: Dr. Thomas Rauch Universitaet Tuebingen, Institut fuer N Astronomie und Astrophysik ------------------------------------------------------------------------------------ 5. Abstract We propose UV spectroscopy of a sample of hot hydrogen-rich central stars of PNe, covering the hottest phase of post-AGB evolution (T_eff > 70 000 K). The spectra shall be analyzed with fully metal line blanketed NLTE model atmospheres in order to determine T_eff, surface gravity, and chemical composition. The results will address the following problems: 1. The temperature scale of the hottest central stars is poorly known. Iron lines, only accessible in the UV, are ideal temperature indicators to set up a reliable temperature scale. 2. Depending on the particular star, the derived metal abundances are either dominated by current diffusion processes or they originate from dredge-up phases during previous AGB evolution. We expect that our sample comprises different objects so that both processes/phases can be studied in detail. 2a. Those objects, which show qualitatively a metal abundance pattern which points at dredge-up phases, can be used to quantitatively check against abundance predictions of stellar evolution theory. 2b. The other objects, where gravitational diffusion and radiative acceleration determine the photospheric metal abundances, will be used to check our NLTE models which for the first time include diffusion processes self-consistently. ------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 2] Observations Description ------------------------ We plan to perform short-slit (0.2*0.2) medium dispersion UV spectroscopy for eight H-rich CSPN in the E140M configuration. This provides the spectral resolution needed for a quantitative analysis of the narrow metal lines and it covers the range 1150-1700 Angstrom . Besides prominent C, N, O lines this range contains many Fe V, Fe VI, and Fe VII as well as Ni V, and Ni VI lines, suitable for spectroscopic analyses. All targets have UV fluxes well known from IUE observations. We used the STIS Exposure Time Calculator to determine the exposure times necessary to achieve S/N ~ 30. Guide star acquisition takes 6 minutes, target acquisition 6 minutes, and guide star reacquisition takes 5 minutes (will be necessary 5 times). Peakup is not necessary because of slit width. The first MAMA exposure in each visit needs 8 minutes overhead. S/N ~ 30 can be reached for three objects within one orbit, while the remaining objects need two orbits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1360- STAR, PLANETARY NEBULA RA=03H 33M 14.63S +/- 0.1", DEC= J2000 V = 11.20+/-0.2 CENSTAR CENTRAL STAR -25D 52' 18.5" +/- 0.1", PLATE- ID=027X Coordinate Source: GUIDE_STAR_CATALOG 2 LSS1362- STAR, PLANETARY NEBULA RA=09H 52M 44.47S +/- 0.1", DEC= J2000 V = 12.50+/-0.2 CENSTAR CENTRAL STAR -46D 16' 48.7" +/- 0.1", PLATE- ID=011L Coordinate Source: GUIDE_STAR_CATALOG 3 LSV+4621- STAR, PLANETARY NEBULA RA=04H 43M 21.27S +/- 0.1", J2000 V = 12.67+/-0.2 CENSTAR CENTRAL STAR DEC=46D 42' 6.1" +/- 0.1", PLATE -ID=003O Coordinate Source: GUIDE_STAR_CATALOG 4 NGC1535- STAR, PLANETARY NEBULA RA=04H 14M 15.79S +/- 0.1", DEC= J2000 V = 10.55+/-0.2 CENSTAR CENTRAL STAR -12D 44' 22.06" +/- 0.1", PLATE- ID=02NH Coordinate Source: HST_IMAGE Comments: The position was measured from WFPC2 images u2sa0501t - u2sa0504t and subsequently averaged. Guide Star Catalogue (copyright, AURA 1989-1998) Position (J2000) : 04 14 15.79 -12 44 22.1 Guide Star ID H M S D M S err Mag err Bp Cl Plt n IIPDGBFN Epoch 5318 563 04 14 15.76 -12 44 23.1 3.6 6.38 0.40 0 00 02NH 3 FFTFFFTF 1984.960 5 NGC7293- STAR, PLANETARY NEBULA RA=22H 29M 38.47S +/- 0.1", DEC= J2000 V = 13.54+/-0.1 CENSTAR CENTRAL STAR -20D 50' 13.6" +/- 0.1", PLATE- ID=04I5 Coordinate Source: GSC_SURVEY_PLATE 6 ABELL36- STAR, PLANETARY NEBULA RA=13H 40M 41.29S +/- 0.1", DEC= J2000 V = 11.50+/-0.2 CENSTAR CENTRAL STAR -19D 52' 54.7" +/- 0.1", PLATE- ID=0178 Coordinate Source: GSC_SURVEY_PLATE 7 NGC6853- STAR, PLANETARY NEBULA RA=19H 59M 36.37S +/- 0.1", J2000 V = 13.94+/-0.2 CENSTAR CENTRAL STAR DEC=22D 43' 16.1" +/- 0.1", PLATE-ID=00FF Coordinate Source: GUIDE_STAR_CATALOG 8 NGC4361- STAR, PLANETARY NEBULA RA=12H 24M 30.67S +/- 0.1", DEC= J2000 V = 13.18+/-0.2 CENSTAR CENTRAL STAR -18D 47' 5.63" +/- 0.1", PLATE- ID=05Y2 Coordinate Source: HST_IMAGE Comments: The position was measured from WFPC2 images u2sa1901t - u2sa1904t and subsequently averaged. Guide Star Catalogue (copyright, AURA 1989-1998) Position (J2000) : 12 24 30.67 -18 47 5.6 Guide Star ID H M S D M S err Mag err Bp Cl Plt n IIPDGBFN Epoch 6105 1129 12 24 28.86 -18 45 28.4 0.3 15.39 0.40 0 01 05Y2 1 FFTFFFFF 1979.453 8638( 4) - 09/08/00 17:51 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC1360-CEN STIS/C ACQ F25ND3 MIRROR 1 3.0 S STAR CD Comments: S/N=63 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC1360-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2366 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 5] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 LSS1362-CEN STIS/C ACQ F25ND3 MIRROR 1 10 S STAR CD Comments: S/N=63 ------------------------------------------------------------------------------------------------------------------------------------ 20 LSS1362-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2469 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 LSS1362-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 3054 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 LSV+4621-CE STIS/C ACQ F25ND3 MIRROR 1 11.0 S NSTAR CD Comments: S/N=61 ------------------------------------------------------------------------------------------------------------------------------------ 20 LSV+4621-CE STIS/F ACCUM 0.2X0.2 E140M 1425 1 2465 S NSTAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 LSV+4621-CE STIS/F ACCUM 0.2X0.2 E140M 1425 1 3054 S NSTAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 7] Visit: 04 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC1535-CEN STIS/C ACQ F25ND3 MIRROR 1 2.0 S STAR CD Comments: S/N=70 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC1535-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2346 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 8] Visit: 05 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC7293-CEN STIS/C ACQ F25ND3 MIRROR 1 24.0 S STAR CD Comments: S/N=60 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC7293-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2265 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC7293-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2900 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 9] Visit: 06 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 ABELL36-CEN STIS/C ACQ F25ND3 MIRROR 1 4.0 S STAR CD Comments: S/N=63 ------------------------------------------------------------------------------------------------------------------------------------ 20 ABELL36-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2336 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 10] Visit: 07 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6853-CEN STIS/C ACQ F25ND3 MIRROR 1 25.0 S STAR CD Comments: S/N=50 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC6853-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2261 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 31 NGC6853-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2906 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 11] Visit: 08 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC4361-CEN STIS/C ACQ F25ND3 MIRROR 1 13 S STAR CD Comments: S/N=51 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC4361-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2261 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC4361-CEN STIS/F ACCUM 0.2X0.2 E140M 1425 1 2897 S STAR UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8638( 4) - 09/08/00 17:51 - [ 12] Summary Form for Proposal 8638 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25ND3 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1360-CENSTAR LSS1362-CENSTAR LSV+4621-CENSTAR NGC1535-CENSTAR NGC7293-CENSTAR ABELL36-CENSTAR NGC6853-CENSTAR NGC4361-CENSTAR ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------