11140( 3) - 05/21/07 10:13 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11140 Version: 3 Check-in Time: 21-May-2007 14:12:34 STScI Edit Number: 0 Title Can mass-ejections from late He-shell flash stars constrain convective/reactive flow modeling of stellar interiors? ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Klaus Werner Universitat Tubingen, Institut fur Astronomie & Astrophysik CoI: Dr. Falk Herwig University of Keele N CoI: Dr. Joachim Koeppen Universite de Strasbourg I N CoI: Dr. Thomas Rauch Universitat Tubingen, Institut fur Y Astronomie & Astrophysik CoI: Dr. Alex Heger University of Chicago N ------------------------------------------------------------------------------------ Abstract The existence of H-deficient knots around the central stars of the planetary nebulae Abell 30 and Abell 78 is still unexplained. We hypothesize that these knots were ejected during a very late helium-shell flash (= very late thermal pulse, VLTP) suffered by the precursor white dwarf stars. If this is true, then the characteristics of these knots (mass, velocity, density, spatial distribution) allow to draw conclusions on the course of the hydrogen-ingestion flash detonation that is triggered by the He-shell flash. This provides important, otherwise inaccessible constraints for the hydrodynamical modeling of convective/reactive flows in stellar interiors. Understanding the physics of these flows is not only important for the understanding of these particular central stars, but also for the frequent, very similar convective/reactive events that determine the nucleosynthesis in Pop. III stars. With this proposal we want to proof or discard the idea that the H-deficient knots are resulting from a VLTP. If true, then they can be exploited for flash- physics diagnostics. We propose a simple test. We search for such knots around five H-deficient central stars (PG1159 stars). Our models predict, that only those stars with residual nitrogen in the atmosphere have suffered a VLTP and, hence, should have expelled knots. We therefore want to take [O III] images of stars which have photospheric N and those which do not. ------------------------------------------------------------------------------------ 11140( 3) - 05/21/07 10:13 - [ 2] Observations Description ------------------------ We want to image faint nebular emission in the close vicinity of our five targets. The images shall be taken with WFPC2/PC1 and the F502N filter. We aim to fill the complete orbit. In order to avoid blooming, the exposures of targets 2 and 4 have to be split up into short exposures. The exposures of targets 1, 3, and 5 are split into two subexposures. This is sufficient for our purpose in order to correct for cosmic-particle contamination. Dithering is used for all targets. We used the WFPC2 ETC for point sources - v4.0 and determined the maximum exposure time to stay below the saturation level. For targets 2 and 4, the orbit planner is used then to get the maximum total exposure time. The target stars are the brightest objects in the FOV. Real Time Justification ----------------------- Calibration Justification ------------------------- Standard calibration is sufficent for our purpose. Additional Comments ------------------- ------------------------------------------------------------------------------------ 11140( 3) - 05/21/07 10:13 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 LONGMORE-4 STAR, PG1159 STAR, RA=10H05M45.7790S +/- 0.1", J2000 V = 16.6 PLANETARY NEBULA DEC=-44D21'33.27" +/- 0.1" CENTRAL STAR, POST-AGB STAR Reference Frame: ICRS 2 NGC-246 STAR, PG1159 STAR, RA=00H47M3.3383S +/- 0.1", DEC=- J2000 V = 11.95 PLANETARY NEBULA 11D52'18.92" +/- 0.1" CENTRAL STAR, POST-AGB STAR Reference Frame: ICRS 3 K1-16 STAR, PG1159 STAR, RA=18H21M52.2110S +/- 0.1", J2000 V = 15.4 PLANETARY NEBULA DEC=+64D21'54.31" +/- 0.1" CENTRAL STAR, POST-AGB STAR Reference Frame: ICRS 4 RXSJ211707.9 STAR, PG1159 STAR, RA=21H17M8.2910S +/- 0.1", J2000 V = 13.2 +341220 PLANETARY NEBULA DEC=+34D12'27.22" +/- 0.1" CENTRAL STAR, POST-AGB STAR Reference Frame: ICRS 5 PG1144+005 STAR, PG1159 STAR, RA=11H46M35.2300S +/- 0.1", J2000 V = 16.2 POST-AGB STAR DEC=+00D12'33.60" +/- 0.1" Reference Frame: ICRS 11140( 3) - 05/21/07 10:13 - [ 4] Visit: 01 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 LONGMORE-4 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 2 LONGMORE-4 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S POS TARG 0.23, 0.23 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ LONGMORE-4 1 WFPC2 IMAGE PC1 F502N none none none none 1 N/A LONGMORE-4 2 WFPC2 IMAGE PC1 F502N none none none none 1 N/A 11140( 3) - 05/21/07 10:13 - [ 5] Visit: 02 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-246 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 4 100 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-246 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 4 100 S POS TARG 0.23, 0.23 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-246 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 4 100 S POS TARG -0.23,-0.23 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-246 1 WFPC2 IMAGE PC1 F502N none none 1 none 1 N/A NGC-246 1 WFPC2 IMAGE PC1 F502N none none 2 none 1 N/A NGC-246 1 WFPC2 IMAGE PC1 F502N none none 3 none 1 N/A NGC-246 1 WFPC2 IMAGE PC1 F502N none none 4 none 1 N/A NGC-246 2 WFPC2 IMAGE PC1 F502N none none 1 none 1 N/A NGC-246 2 WFPC2 IMAGE PC1 F502N none none 2 none 1 N/A NGC-246 2 WFPC2 IMAGE PC1 F502N none none 3 none 1 N/A NGC-246 2 WFPC2 IMAGE PC1 F502N none none 4 none 1 N/A NGC-246 3 WFPC2 IMAGE PC1 F502N none none 1 none 1 N/A NGC-246 3 WFPC2 IMAGE PC1 F502N none none 2 none 1 N/A NGC-246 3 WFPC2 IMAGE PC1 F502N none none 3 none 1 N/A NGC-246 3 WFPC2 IMAGE PC1 F502N none none 4 none 1 N/A 11140( 3) - 05/21/07 10:13 - [ 6] Visit: 03 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 K1-16 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S ------------------------------------------------------------------------------------------------------------------------------------ 2 K1-16 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S POS TARG 0.23, 0.23 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ K1-16 1 WFPC2 IMAGE PC1 F502N none none none none 1 N/A K1-16 2 WFPC2 IMAGE PC1 F502N none none none none 1 N/A 11140( 3) - 05/21/07 10:13 - [ 7] Visit: 04 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 RXSJ211707. WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 3 260 S 9+341220 ------------------------------------------------------------------------------------------------------------------------------------ 2 RXSJ211707. WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 3 260 S 9+341220 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ RXSJ211707.9+34122 1 WFPC2 IMAGE PC1 F502N none none 1 none 1 N/A 0 RXSJ211707.9+34122 1 WFPC2 IMAGE PC1 F502N none none 2 none 1 N/A 0 RXSJ211707.9+34122 1 WFPC2 IMAGE PC1 F502N none none 3 none 1 N/A 0 RXSJ211707.9+34122 2 WFPC2 IMAGE PC1 F502N none none 1 none 1 N/A 0 RXSJ211707.9+34122 2 WFPC2 IMAGE PC1 F502N none none 2 none 1 N/A 0 RXSJ211707.9+34122 2 WFPC2 IMAGE PC1 F502N none none 3 none 1 N/A 0 11140( 3) - 05/21/07 10:13 - [ 8] Visit: 05 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG1144+005 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 2 PG1144+005 WFPC2 IMAGE PC1 F502N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PG1144+005 1 WFPC2 IMAGE PC1 F502N none none none none 1 N/A PG1144+005 2 WFPC2 IMAGE PC1 F502N none none none none 1 N/A 11140( 3) - 05/21/07 10:13 - [ 9] Summary Form for Proposal 11140 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.23, 0.23; POS TARG -0.23,-0.23; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F502N ------------------------------------------------------------------------------------------------------------------------------------ Target Names LONGMORE-4 NGC-246 K1-16 RXSJ211707.9+341220 PG1144+005 ------------------------------------------------------------------------------------------------------------------------------------