12906( 8) - 15-May-2013 18:57:46 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12906 Version: 8 Check-in Time: 15-May-2013 18:57:46 STScI Edit Number: 5 Title Chemical composition of an exo-planetary debris disk ------------------------------------------------------------------------------------ Type Cycle GO 20 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Klaus Werner Eberhard Karls Universitat, Tubingen Y CoI: Stephan Hartmann Eberhard Karls Universitat, Tubingen N CoI: Dr. Thorsten Nagel Eberhard Karls Universitat, Tubingen N CoI: Dr. Thomas Rauch Eberhard Karls Universitat, Tubingen N ------------------------------------------------------------------------------------ Abstract In the recent years, four white dwarfs with gaseous planetary debris disk were discovered. It is thought that they were created by tidally disrupted planetary bodies. This offers the unique possibility to determine directly the composition of exo-planetary material by spectroscopic means. However, only very few bright emission lines from the optically thin gas disk are detectable because the white dwarf's photospheric flux in the near-IR to UV spectral band is rather strong. Here we propose to perform far-UV observations of one of these WDs shortward of 115 nm where the WD flux is effectively blocked by broad and deep photospheric hydrogen Lyman lines. We expect to detect disk emission lines from carbon and silicon. Together with optical and near-UV archival spectra that exhibit lines from Ca, Mg, and Fe, this enables us for the first time to determine the relative abundances of most of the abundant elements in the disk. In particular, we may decide whether the planetary debris was formed from chondritic or bulk-Earth like material. ------------------------------------------------------------------------------------ Observations Description ------------------------ We want to observe our single target for 4 orbits with COS/G130M with central wavelength setting 1096 A, where Segments B and A cover 940-1080 A and 1096-1236 A, respectively. Orbit 1: guide star and target acquisition; science overhead; science integration Orbits 2-4: guide star re-acquisition; science overhead; science integration FP-POS change: Each orbit is at one different position, i.e., no overhead In total, we will achieve S/N=2-4 in the 905-1050A range (when binned over 6px). Further binning to sufficient 2A resolution yields S/N=12-23. At longer wavelengths, S/N increases strongly, e.g. S/N>50 at 1110A. Real Time Justification ----------------------- Calibration Justification 12906( 8) - 15-May-2013 18:57:46 - [ 2] ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12906( 8) - 15-May-2013 18:57:46 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ122859. STAR, DA RA=12H28M59.9300S +/- 0.1", J2000 V = 16.5 +/- 0.1 6.0E-14 erg/cm2/s/A @ 93+104032.9 DEC=+10D40'32.90" +/- 0.1" 1150 A Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2002.94 -0.003188523126586861 -0.025 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 12906( 8) - 15-May-2013 18:57:46 - [ 4] Visit: 01 Visit Requirements: SCHED 100% 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 SDSSJ122859 COS/FUV ACQ/SEA PSA G130M 1309 SCAN-SIZE=3, 1 2.5 S .93+104032. RCH CENTER=FLUX-WT-FLR, 9 STEP-SIZE=1.767 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ122859 COS/FUV ACQ/PEA PSA G130M 1309 1 2.5 S .93+104032. KXD 9 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ122859 COS/FUV ACQ/PEA PSA G130M 1309 CENTER=FLUX-WT-FLR, NUM-POS=5, 1 2.5 S .93+104032. KD SEGMENT=BOTH, STEP-SIZE=0.9 9 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=1649, FP-POS=1, 1 1905 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=2, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=3, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 7 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=4, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ122859.93+1040 1 COS/FUV ACQ/SEA PSA G130M 1309 none none none none 1 N/A 32.9 RCH SDSSJ122859.93+1040 2 COS/FUV ACQ/PEA PSA G130M 1309 none none none none 1 N/A 32.9 KXD SDSSJ122859.93+1040 3 COS/FUV ACQ/PEA PSA G130M 1309 none none none none 1 N/A 32.9 KD SDSSJ122859.93+1040 4 COS/FUV TIME-TA PSA G130M 1096 none none none none 1 N/A 32.9 G 12906( 8) - 15-May-2013 18:57:46 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ122859.93+1040 5 COS/FUV TIME-TA PSA G130M 1096 none none none none 2 N/A 32.9 G SDSSJ122859.93+1040 6 COS/FUV TIME-TA PSA G130M 1096 none none none none 3 N/A 32.9 G SDSSJ122859.93+1040 7 COS/FUV TIME-TA PSA G130M 1096 none none none none 4 N/A 32.9 G 12906( 8) - 15-May-2013 18:57:46 - [ 6] Visit: 51 Visit Requirements: SCHED 100% 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 SDSSJ122859 COS/FUV ACQ/SEA PSA G130M 1309 SCAN-SIZE=3, 1 2.5 S GS ACQ SCENARIO BASE1B3 .93+104032. RCH CENTER=FLUX-WT-FLR, 9 STEP-SIZE=1.767 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ122859 COS/FUV ACQ/PEA PSA G130M 1309 1 2.5 S .93+104032. KXD 9 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ122859 COS/FUV ACQ/PEA PSA G130M 1309 CENTER=FLUX-WT-FLR, NUM-POS=5, 1 2.5 S .93+104032. KD SEGMENT=BOTH, STEP-SIZE=0.9 9 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=1649, FP-POS=1, 1 1905 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=2, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=3, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 7 SDSSJ122859 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2207, FP-POS=4, 1 2729 S .93+104032. G SEGMENT=BOTH, FLASH=YES, 9 EXTENDED=NO ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ122859.93+1040 1 COS/FUV ACQ/SEA PSA G130M 1309 none none none none 1 N/A 32.9 RCH SDSSJ122859.93+1040 2 COS/FUV ACQ/PEA PSA G130M 1309 none none none none 1 N/A 32.9 KXD SDSSJ122859.93+1040 3 COS/FUV ACQ/PEA PSA G130M 1309 none none none none 1 N/A 32.9 KD SDSSJ122859.93+1040 4 COS/FUV TIME-TA PSA G130M 1096 none none none none 1 N/A 32.9 G 12906( 8) - 15-May-2013 18:57:46 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ122859.93+1040 5 COS/FUV TIME-TA PSA G130M 1096 none none none none 2 N/A 32.9 G SDSSJ122859.93+1040 6 COS/FUV TIME-TA PSA G130M 1096 none none none none 3 N/A 32.9 G SDSSJ122859.93+1040 7 COS/FUV TIME-TA PSA G130M 1096 none none none none 4 N/A 32.9 G 12906( 8) - 15-May-2013 18:57:46 - [ 8] Summary Form for Proposal 12906 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAKD, ACQ/PEAKXD, ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1649, BUFFER-TIME=2207, CENTER=FLUX-WT-FLR, EXTENDED=NO, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, NUM-POS=5, SCAN-SIZE=3, SEGMENT=BOTH, STEP-SIZE=0.9, STEP-SIZE=1.767 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ122859.93+104032.9 ------------------------------------------------------------------------------------------------------------------------------------