17190( 3) - 15-Feb-2023 20:39:35 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17190 Version: 3 Check-in Time: 15-Feb-2023 20:39:35 STScI Edit Number: 1 Title Will the Recurrent Nova T Pyxidis Become a Type Ia Supernova? ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Patrick Godon Villanova University Y CoI: Prof. Edward M. Sion Villanova University N CoI: Dr. Robert E. Williams Space Telescope Science Institute N CoI: Prof. Matthew James Darnley Liverpool John Moores University N ------------------------------------------------------------------------------------ Abstract The recurrent nova T Pyx has erupted six times since 1890. The last outburst in 2011 offered a unique opportunity to catch T Pyx with HST as it transited into quiescence. The system has now passed its nebular phase and settled into a deep quiescence state where the UV and optical emissions are dominated by the accretion disk. Earlier HST COS observations have provided FUV spectroscopy showing the decline phase and indicating that T Pyx is accreting at a very high rate. As a result, the T Pyx WD might be growing in mass, and therefore may be on its way to explode as a Type Ia supernova (SN Ia). HST STIS optical spectra were obtained during the nebular phase to study the expanding nebular material, but no STIS optical spectra have yet been obtained during the quiescent phase to help derive an accurate mass accretion rate: to model the disk properly UV and optical spectra must be collected because the inner disk dominates in the FUV and the outer disk dominates in the optical. We request the first combined optical (STIS) and FUV (COS) spectroscopic observation of T Pyx during the deep quiescent phase to properly model the disk and derive an accurate mass accretion rate. In addition, we will measure the width and velocity of the hydrogen and helium lines to better model the inner disk (lines in emission) and outer disk (lines in absorption). These observations will assess whether the T Pyx WD mass is growing, and hence whether T Pyx is indeed a viable SN Ia progenitor. Even though SNe Ia are the tools used to demonstrate that the Universe is accelerating, the exact nature of SN Ia progenitors has not been confirmed. ------------------------------------------------------------------------------------ Observations Description ------------------------ In order to obtain a broad spectral coverage of the target T Pyxidis (covering the UV and Optical), we request two sets of observations, each for 2 orbits, totalling 4 orbits. The first set (visit) is configured in the COS/FUV Spectroscopic mode for two orbits. The first orbit with the G140L spectral element centered at 1105 Angstrom. The second orbit, following immediately the first COS one above, with the G130M spectral element centered at 1055 Angstrom. Both with the PSA Aperture. The second set (visit) is configured in the (optical) STIS/CCD Spectroscopic 17190( 3) - 15-Feb-2023 20:39:35 - [ 2] mode for two orbits. The first orbit with the G750L grating centered at 7751 Angstrom. The second orbit, following immediately the first STIS one above, with the G430L grating centered at 4300 Angstrom. Both in ACCUM mode, with the 52x0.1E1 aperture. The E1 aperture was chosen for STIS as the ETC warns about a low electron per pixel causing poor CTE. Since we are using the G750L (7751) configuration we also added a flat field exposure (2 iteration) to allow for correction of the fringes appearing above 7000 Angstroms. The two visits should ideally be spaced as close as possible in time, we request a separation between them of 1 orbit to one month (about 500 orbits) - the target luminosity is not expected to undergo any detectable change over this period of time (though over a few months to a year it may show a slight decrease). Since T Pyx is a variable (a recurrent nova), we will request the AAVSO to monitor it to make sure it doesn't (unexpectedly) erupt (its last eruption was 11 years ago, and the time between eruptions is 20-40 years). Such eruptions have short timescales (days) and may require the safe target offset procedure (STOP) to which we will fully comply (the AAVSO can provide photometric monitoring for more than 7 consecutive days leading to the HST observations and within 24 hours of the target being observed by HST - for the two visits). ------------------------------------------------------------------------------------ 17190( 3) - 15-Feb-2023 20:39:35 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA-PYX-189 STAR, ACCRETION DISK, RA=09H04M41.5062S +/- 0.0157", J2000 V = 15.1 +/- 0.6 0 RECURRENT NOVA DEC=-32D22'47.50" +/- 0.0212" Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2020 -1.9624647953839734E-4 1.52E-4 0.3467E-3 ------------------------------------------------------------------------------------------------------------------------------------ 2 NOVA-PYX-189 UNIDENTIFIED, BLANK RA-OFF=0.01S, DEC-OFF=9.492", J2000 V = 15.1 +/- 0.6 0-SAFE-TARGE FIELD FROM 1 T Extended: NO Comments: This target is a blank piece of sky which is the bright object safe pointing and is 9.494 arcseconds away at a PA 1.3 degrees from NOVA-PYX-1890 ------------------------------------------------------------------------------------------------------------------------------------ 17190( 3) - 15-Feb-2023 20:39:35 - [ 4] Visit: 01 (COS FUV) Visit Requirements: ORIENT 215D TO 55 D On Hold Comments: Additional Comments: This should be scheduled in evening-local time. Flags need to be cleared during the work day. Weekends are to be avoided since the CS must clear the target within 24 hours of HST execution. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA-PYX-18 COS/FUV ACQ/PEA PSA G140L 1105 LIFETIME-POS=LP4 1 7.4 S (7.4 USE OFFSET V01SAF 90 KXD S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NOVA-PYX-18 COS/FUV ACQ/PEA PSA G140L 1105 NUM-POS=5.0, STEP-SIZE=0.9, 1 7.4 S (7.4 USE OFFSET V01SAF 90 KD CENTER=FLUX-WT-FLR, S) LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 3 NOVA-PYX-18 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=2000, FP-POS=ALL, 1 550 S USE OFFSET V01SAF 90 G LIFETIME-POS=LP3 see below (1912 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NOVA-PYX-18 COS/FUV TIME-TA PSA G130M 1055 BUFFER-TIME=8000, FP-POS=ALL, 1 550 S USE OFFSET V01SAF 90 G LIFETIME-POS=LP2 see below (2404 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 | ------------------------------------------------------------------------------------------------------------------------------------ NOVA-PYX-1890 1 COS/FUV ACQ/PEA PSA G140L 1105 none none none none 1 N/A KXD NOVA-PYX-1890 2 COS/FUV ACQ/PEA PSA G140L 1105 none none none none 1 N/A KD NOVA-PYX-1890 3 COS/FUV TIME-TA PSA G140L 1105 none none none 1 1 478.0 S G NOVA-PYX-1890 3 COS/FUV TIME-TA PSA G140L 1105 none none none 2 1 478.0 S G NOVA-PYX-1890 3 COS/FUV TIME-TA PSA G140L 1105 none none none 3 1 478.0 S G NOVA-PYX-1890 3 COS/FUV TIME-TA PSA G140L 1105 none none none 4 1 478.0 S G NOVA-PYX-1890 4 COS/FUV TIME-TA PSA G130M 1055 none none none 1 2 601.0 S G NOVA-PYX-1890 4 COS/FUV TIME-TA PSA G130M 1055 none none none 2 2 601.0 S G NOVA-PYX-1890 4 COS/FUV TIME-TA PSA G130M 1055 none none none 3 2 601.0 S G 17190( 3) - 15-Feb-2023 20:39:35 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ NOVA-PYX-1890 4 COS/FUV TIME-TA PSA G130M 1055 none none none 4 2 601.0 S G 17190( 3) - 15-Feb-2023 20:39:35 - [ 6] Visit: 02 (STIS CCD Optical) Visit Requirements: AFTER 01 BY 1 Orbits TO 500 Orbits 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA-PYX-18 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 5 S (5 S) 90 ------------------------------------------------------------------------------------------------------------------------------------ 2 NOVA-PYX-18 STIS/CCD ACQ/PEA 52X0.1E1 MIRROR 1 5 S (5 S) 90 K ------------------------------------------------------------------------------------------------------------------------------------ 3 NOVA-PYX-18 STIS/CCD ACCUM 52X0.1E1 G430L 4300 CR-SPLIT=8 1 2200 S 90 see below (1699.4 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NOVA-PYX-18 STIS/CCD ACCUM 52X0.1E1 G750L 7751 CR-SPLIT=8 1 2200 S 90 see below (2340.4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 DEF (0 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 | ------------------------------------------------------------------------------------------------------------------------------------ NOVA-PYX-1890 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A NOVA-PYX-1890 2 STIS/CCD ACQ/PEA 52X0.1E1 MIRROR none none none none 1 N/A K NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 1 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 2 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 3 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 4 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 5 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 6 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 7 1 209.2 S NOVA-PYX-1890 3 STIS/CCD ACCUM 52X0.1E1 G430L 4300 none none none 8 1 235.0 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 1 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 2 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 3 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 4 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 5 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 6 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 7 2 302.2 S NOVA-PYX-1890 4 STIS/CCD ACCUM 52X0.1E1 G750L 7751 none none none 8 2 225.0 S CCDFLAT 5 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 2 N/A 17190( 3) - 15-Feb-2023 20:39:35 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ CCDFLAT 5 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 2 N/A 17190( 3) - 15-Feb-2023 20:39:35 - [ 8] Visit: 03 (S/C Visit for Visit 01) Visit Requirements: ORIENT 215D TO 55 D On Hold Comments: Additional Comments: This visit allocates and sets up the safe position offset slot for Visit 01 which will use that slot. This S/C visit should go earlier in the week while visit 01 will be at least 3 days later. The S/C visit will contain only 1 exposure. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA-PYX-18 S/C DATA V1 1 5 S (5 S) POS TARG 229.1328, 90 -241.0575; SAVE OFFSET V01SAF; SPEC COM INSTR ECSLOTSET; QESIPARM ANGLE 1.3; QESIPARM DIST 9.494 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NOVA-PYX-1890 1 S/C DATA V1 none none none none 1 N/A 17190( 3) - 15-Feb-2023 20:39:35 - [ 9] Visit: 04 (BOP Visit for Visit 01) Visit Requirements: ORIENT 215D TO 55 D On Hold Comments: Additional Comments: This visit is for BOP checking the safe target only and should not execute onboard HST Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NOVA-PYX-18 COS/FUV ACQ/PEA PSA G140L 1105 LIFETIME-POS=LP4 1 7.4 S (7.4 90-SAFE-TAR KXD S) GET ------------------------------------------------------------------------------------------------------------------------------------ 2 NOVA-PYX-18 COS/FUV ACQ/PEA PSA G140L 1105 NUM-POS=5.0, STEP-SIZE=0.9, 1 7.4 S (7.4 90-SAFE-TAR KD CENTER=FLUX-WT-FLR, S) GET LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 3 NOVA-PYX-18 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=2000, FP-POS=ALL, 1 550 S 90-SAFE-TAR G LIFETIME-POS=LP3 see below GET (1912 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NOVA-PYX-18 COS/FUV TIME-TA PSA G130M 1055 BUFFER-TIME=8000, FP-POS=ALL, 1 550 S 90-SAFE-TAR G LIFETIME-POS=LP2 see below GET (2404 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 | ------------------------------------------------------------------------------------------------------------------------------------ NOVA-PYX-1890-SAFE- 1 COS/FUV ACQ/PEA PSA G140L 1105 none none none none 1 N/A TARGET KXD NOVA-PYX-1890-SAFE- 2 COS/FUV ACQ/PEA PSA G140L 1105 none none none none 1 N/A TARGET KD NOVA-PYX-1890-SAFE- 3 COS/FUV TIME-TA PSA G140L 1105 none none none 1 1 478.0 S TARGET G NOVA-PYX-1890-SAFE- 3 COS/FUV TIME-TA PSA G140L 1105 none none none 2 1 478.0 S TARGET G NOVA-PYX-1890-SAFE- 3 COS/FUV TIME-TA PSA G140L 1105 none none none 3 1 478.0 S TARGET G NOVA-PYX-1890-SAFE- 3 COS/FUV TIME-TA PSA G140L 1105 none none none 4 1 478.0 S TARGET G NOVA-PYX-1890-SAFE- 4 COS/FUV TIME-TA PSA G130M 1055 none none none 1 2 601.0 S TARGET G NOVA-PYX-1890-SAFE- 4 COS/FUV TIME-TA PSA G130M 1055 none none none 2 2 601.0 S TARGET G NOVA-PYX-1890-SAFE- 4 COS/FUV TIME-TA PSA G130M 1055 none none none 3 2 601.0 S TARGET G NOVA-PYX-1890-SAFE- 4 COS/FUV TIME-TA PSA G130M 1055 none none none 4 2 601.0 S TARGET G 17190( 3) - 15-Feb-2023 20:39:35 - [ 10] Summary Form for Proposal 17190 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.1, 52X0.1E1, F28X50LP, PSA, V1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, S/C, STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/PEAK, ACQ/PEAKD, ACQ/PEAKXD, DATA, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, BUFFER-TIME=2000, BUFFER-TIME=8000, CENTER=FLUX-WT-FLR, CR-SPLIT=8, FP-POS=ALL, LIFETIME-POS=LP2, LIFETIME-POS=LP3, LIFETIME-POS=LP4, NUM-POS=5.0, STEP-SIZE=0.9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 1 Orbits TO 500 Orbits, ORIENT 215D TO 55 D, POS TARG 229.1328, -241.0575, QESIPARM ANGLE 1.3, QESIPARM DIST 9.494, SAVE OFFSET V01SAF, SPEC COM INSTR ECSLOTSET, USE OFFSET V01SAF ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G140L, G430L, G750L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names CCDFLAT, NOVA-PYX-1890, NOVA-PYX-1890-SAFE-TARGET ------------------------------------------------------------------------------------------------------------------------------------