8782( 2) - 02/28/00 16:22 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8782 Version: 2 Check-in Date: 28-Feb-2000 16:21:37 1.Proposal Title: The next bright Galactic nova: High Resolution Imaging ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Michael Shara American Museum of Natural History CoI: Dr. Mario Livio Space Telescope Science Institute N CoI: Dr. Dina Prialnik Tel-Aviv University N CoI: Dr. Robert Williams Space Telescope Science Institute N CoI: Mr. David Zurek Space Telescope Science Institute N ------------------------------------------------------------------------------------ 5. Abstract The recurrent nova T Pyxidis is one of only ~20 novae with known shells, and the only recurrent nova with clearly resolved circumstellar matter. A unique and once-in -a- generation opportunity will exist during T Pyxidis' next eruption (now overdue) to determine: 1) The uniformity and isotropy of material (both dust and different chemical elements) ejected in previous eruptions, and 2) The smallest structures formed in nova eruptions. We propose to use WFPC2 to image T Pyx after it erupts to search for fluorescence and reflection light echoes from, and small-scale structure in, the nova circumstellar gas and dust ejecta. Only two novae are presently known to have a highly structured shell that can be defined as ``very'' clumpy. These novae are GK Per (known from the ground) and T Pyx (HST cycle 4 WFPC2 images). It's unclear if this structure is common to all nova shells or, if it is, how the structure is created. Though T Pyx is ``overdue'' it may take several years before it goes off again. We therefore propose to use the TOO time, if allocated, to follow the eruption of the next bright Galactic nova with WFPC2 (if T Pyx does not erupt) to determine how quickly the ejecta of a nova become clumpy. ------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 2] Observations Description ------------------------ Should T Pyx erupt during cycle 8, we request that (as soon as possible) we image for 3 orbits in the narrowband filters of Hydrogen, Nitrogen, Oxygen and Helium as well as blue and red broadband filters. We then request that T Pyx be reobserved for 3 orbits one week later, 3 weeks later, 7 weeks later, 16 weeks later, 24 weeks later and then every six months for the next 2 years. If a bright Galactic nova erupts (and T Pyx has not yet erupted) then we request that this nova be acquired ~2 to 3 weeks after maximum and be imaged for 3 orbits with the same filters as T Pyx. We then request that the nova be reimaged once every 3 to 4 months to monitor the ejecta development. Real Time Justification ----------------------- T Pyx is overdue to erupt. Should T Pyx erupt in cycle 8 we request that HST begin observations as soon as possible (ie. <~7 days). A bright Galactic nova (m_max <~ 7) occurs every few years and thus it is quite likely that such an event will occur during cycle 8. We request that once a bright Galactic nova has erupted that HST observations begin within two weeks of maximum light. None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 3] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA2000 STAR, CLASSICAL NOVA, OTHER: A GALACTIC NOVA (EX. T V = 7.0+/-1.0 RECURRENT NOVA, ISM, PYXIDIS) WHICH REACHES A VISUAL EJECTA, SHELL MAGNITUDE GREATER THAN 7. Comments: Standard generic target for a nova. ------------------------------------------------------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ON HOLD PCS MODE FINE On Hold Comments: On hold until a suitable object is discovered. 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 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2600 S ------------------------------------------------------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ON HOLD PCS MODE FINE On Hold Comments: On hold until a suitable object is discovered. 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 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2600 S ------------------------------------------------------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ON HOLD PCS MODE FINE On Hold Comments: On hold until a suitable object is discovered. 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 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 NOVA2000 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 1 2600 S ------------------------------------------------------------------------------------------------------------------------------------ 8782( 2) - 02/28/00 16:22 - [ 7] Summary Form for Proposal 8782 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ON HOLD PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F656N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NOVA2000 ------------------------------------------------------------------------------------------------------------------------------------