6336( 3) - 06/18/96 10:25 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6336 Version: 3 Check-in Date: 18-Jun-1996 10:23:03 1.Proposal Title: The Structure of Nova Shells ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: MICHAEL SHARA SPACE TELESCOPE SCIENCE INSTITUTE CoI: Mario Livio Space Telescope Science Institute N CoI: Dina Prialnik Tel-Aviv University N CoI: Robert Williams Space Telescope Science Institute N CoI: David Zurek Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract Recent WFPC2 observations of the recurrent nova T Pyxidis show that the ejected material from the previous eruptions is neither uniform nor isotropic. Rather, the ejecta is distributed in hundreds of unresolved knots. If this result is the norm for all nova ejecta then all previous mass estimates and ejection models for nova shells are probably incorrect. Observationally determined masses of nova shells provide a very important test to the nova theory. We are proposing to use WFPC2 to determine if 1) all nova shells are in fact broken into knots, and, for the closest shells, 2) to determine the size distribution of these knots. In addition WFPC2 observations of T Pyxidis will enable us to determine whether the clumpy shell is expanding. Finally, we are asking for a reendorsement (granted in cycles 1 and 4) to observe the effects of the next eruption of T Pyx (once in a generation and now several years overdue) on its multitude of circumstellar knots. ------------------------------------------------------------------------------------ 6336( 3) - 06/18/96 10:25 - [ 2] Observations Description ------------------------ We will image the shell of T Pyx to ensure that the knot(s) of interest are still the brightest knots. Then approximately 3 weeks later we will point FOS at the desired knot. We will first peak up on the central star (T Pyx itself) and then offset to the desired knot. Since this is at most 4.5 arcseconds away it should have a very low error on pointing. Finally, several weeks to months after the spectra we will once again image T Pyx to determine if the knot(s) for which we have spectra has decreased in luminosity. Real Time Justification ----------------------- None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6336( 3) - 06/18/96 10:25 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 T-PYXIDIS STAR, RECURRENT NOVA, RA=9H 04M 41.500S +/- 0.02S,DEC= 2000 V = 14.5+/-0.5 SHELL -32D 22' 47.00" +/- 0.2",PLATE- B-V = 0.12+/-0.05 ID=04J9 U-B = -0.96+/-0.05 E(B-V) = 0.35+/-0.05 2 T-PYX-KNOT-1 ISM, EMISSION LINE RA-OFF=0.3502S +/- 0.02S,DEC- 2000 F-LINE(6588)=3.83+/-0.04e-17 NEBULA, EJECTA, KNOT, OFF=0.753" +/- 0.2",FROM 1,PLATE SHELL -ID=04J9 6336( 3) - 06/18/96 10:25 - [ 4] Visit: 01 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: Note that this visit is to ensure that the knot we wish to obtain spectra for is still there and is still the brightest knot. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 T-PYXIDIS WFPC2 IMAGE PC1 F658N CR-SPLIT = 0.5,CR-TOLERANCE = 0.0 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 6336( 3) - 06/18/96 10:25 - [ 5] Visit: 02 Visit Requirements: PCS MODE Fine AFTER 1 BY 28d TO 35d 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 T-PYXIDIS FOS/RD ACQ/PEA 4.3 MIRROR SCAN-STEP-Y=1.23,SEARCH-SIZE-Y=3, 1 0.2 S ONBOARD ACQuisition FOR K SEARCH-SIZE-X=1 2-6 ------------------------------------------------------------------------------------------------------------------------------------ 2 T-PYXIDIS FOS/RD ACQ/PEA 1.0 MIRROR SCAN-STEP-Y=0.61,SCAN-STEP-X=0.61 1 0.2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=2,SEARCH-SIZE-X=6 3-6 ------------------------------------------------------------------------------------------------------------------------------------ 3 T-PYXIDIS FOS/RD ACQ/PEA 0.5 MIRROR SCAN-STEP-Y=0.29,SCAN-STEP-X=0.29 1 0.2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=3,SEARCH-SIZE-X=3 4-6 ------------------------------------------------------------------------------------------------------------------------------------ 4 T-PYXIDIS FOS/RD ACQ/PEA 0.3 MIRROR SCAN-STEP-Y=0.11,SCAN-STEP-X=0.11 1 2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=4,SEARCH-SIZE-X=4 5-6 ------------------------------------------------------------------------------------------------------------------------------------ 5 T-PYX-KNOT- FOS/RD ACCUM 0.5 G400H 3238-47 3 2400 S 1 81 ------------------------------------------------------------------------------------------------------------------------------------ 6 T-PYX-KNOT- FOS/RD ACCUM 0.5 G570H 4571-68 3 2400 S 1 20 ------------------------------------------------------------------------------------------------------------------------------------ 6336( 3) - 06/18/96 10:25 - [ 6] Visit: 03 Visit Requirements: PCS MODE Fine AFTER 1 BY 28d TO 35d 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 T-PYXIDIS FOS/RD ACQ/PEA 4.3 MIRROR SCAN-STEP-Y=1.23,SEARCH-SIZE-Y=3, 1 0.2 S ONBOARD ACQuisition FOR K SEARCH-SIZE-X=1 2-6 ------------------------------------------------------------------------------------------------------------------------------------ 2 T-PYXIDIS FOS/RD ACQ/PEA 1.0 MIRROR SCAN-STEP-Y=0.61,SCAN-STEP-X=0.61 1 0.2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=2,SEARCH-SIZE-X=6 3-6 ------------------------------------------------------------------------------------------------------------------------------------ 3 T-PYXIDIS FOS/RD ACQ/PEA 0.5 MIRROR SCAN-STEP-Y=0.29,SCAN-STEP-X=0.29 1 0.2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=3,SEARCH-SIZE-X=3 4-6 ------------------------------------------------------------------------------------------------------------------------------------ 4 T-PYXIDIS FOS/RD ACQ/PEA 0.3 MIRROR SCAN-STEP-Y=0.11,SCAN-STEP-X=0.11 1 2 S ONBOARD ACQuisition FOR K ,SEARCH-SIZE-Y=4,SEARCH-SIZE-X=4 5-6 ------------------------------------------------------------------------------------------------------------------------------------ 5 T-PYX-KNOT- FOS/RD ACCUM 0.5 G400H 3238-47 3 2400 S 1 81 ------------------------------------------------------------------------------------------------------------------------------------ 6 T-PYX-KNOT- FOS/RD ACCUM 0.5 G570H 4571-68 3 2400 S 1 20 ------------------------------------------------------------------------------------------------------------------------------------ 6336( 3) - 06/18/96 10:25 - [ 7] Summary Form for Proposal 6336 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT = 0.5 CR-TOLERANCE = 0.0 SEARCH-SIZE-X=1 SEARCH-SIZE-X=6 SEARCH-SIZE-X=3 SEARCH-SIZE-X=4 SEARCH-SIZE-Y=3 SEARCH-SIZE-Y=2 SCAN-STEP-X=0.29 SEARCH-SIZE-Y=4 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine PCS MODE Fine AFTER 1 BY 28d TO 35d ONBOARD ACQuisition FOR 2-6 ONBOARD ACQuisition FOR 3-6 ONBOARD ACQuisition FOR 4-6 ONBOARD ACQuisition FOR 5-6 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F658N MIRROR G400H G570H ------------------------------------------------------------------------------------------------------------------------------------ Target Names T-PYXIDIS T-PYX-KNOT-1 ------------------------------------------------------------------------------------------------------------------------------------