17186( 3) - 27-Sep-2022 17:11:50 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17186 Version: 3 Check-in Time: 27-Sep-2022 17:11:50 STScI Edit Number: 0 Title The Origins and Evolution of Helium Atmosphere White Dwarfs ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Judith L. Provencal University of Delaware Y CoI: Dr. Atsuko Nitta NOIRLab - Gemini North (HI) N CoI: Dr. Scot Kleinman NOIRLab - Gemini North (HI) N CoI: Dr. Michael Montgomery University of Texas at Austin N ------------------------------------------------------------------------------------ Abstract Aims: The proposed observations will conduct the first UV investigation helium atmosphere white dwarfs found within the "DB gap", and will determine their physical parameters. Context: The origin and evolution of helium atmosphere white dwarfs (DBs) is poorly constrained. White dwarfs are structurally simple; they consist of an electron degenerate core surrounded by an insulating blanket of hydrogen (DA) and/or helium (DB). Their evolution is dominated by secular cooling. The DB gap is a temperature range between 45, 000 and 30, 000 K where mostly DA white dwarfs are found. There is no readily apparent reason why this should be, so theories of white dwarf formation and evolution have been forced to scenarios that explain this gap. The Sloan Digital Sky Survey has revealed a population of DB white dwarfs that lie within this gap. Little is known about these objects besides their optical temperatures. The fundamental physical properties and chemical abundances of these objects can be used to test competing theories of white dwarf formation and evolution, leading to a better understanding of the white dwarf population and the final stages of stellar evolution. Methods: The proposal presents justification for COS observations of 2 DB white dwarfs with temperatures between 45, 000 and 30, 000 K. The observations will determine accurate effective temperatures, surface gravities and chemical abundances for each. ------------------------------------------------------------------------------------ Observations Description ------------------------ The proposed observations will conduct the first UV investigation of helium atmosphere white dwarfs found within the "DB gap", and will determine their 17186( 3) - 27-Sep-2022 17:11:50 - [ 2] physical parameters. The scientific goal is to constrain theories of the origins and evolution of white dwarf stars. We have two targets: SDSSJ170727.11+203153.25 and SDSSJ141127.09+035429.70. These targets were chosen from the sample of DB stars in Genest-Beaulieu & Bergeron (2019). SDSSJ170727 has a temperature of 44000 K and is near the blue edge of the DB gap. SDSSJ141127, with a temperature of 35600 K, is near the red edge of the DB gap. The observations are relatively straight forward. We have selected the gratings and central wavelengths to detect photospheric lines of hydrogen, carbon, oxygen, silicon and other elements in the spectra of the two targets. White dwarf stars are known for their nearly pure photospheres of either hydrogen or helium, at least at optical wavelengths. The UV wavelength range, however, contains numerous sensistive transitions that are important for determining trace abundances of the elements of interest. Given the limits on Lyman alpha observations with G130M, we have decided to iinclude a hydrogen line at 1025 Angstroms. The G130M grating with a central wavelength of 1096 Angstroms will access HI 1025 Angstroms, CII 1037 Angstroms, CIII 1175 Angstroms, CI 1993 Angstroms, and Si II at 1193 Angstroms. G130M with a central wavelength of 1222 Angstroms will cover SiII 1260, 1264 Angstroms, OII 1305 Angstroms, and CII 1335 Angstroms, The limitations of the response of G160M at certain wavelengths were not as significant to our science as first anticipated, so we have included this grating. G160M with a central wavelength of 1589 Angstroms will cover HeII 1640 as well as SiII lines at 1533 Angstroms. Measuring the strengths of photospheric lines from different transitions such as CII and CIII can be an important diagnostic for temperature. A second method to determine temperature is these hot objects is to measure the slope of the UV continuum. G140L combined with the G130M and G160M grating observations will result in a detailed measurement of the UV flux. between 916 nad 2148 Angstroms. The temperature determined from these measurements will confirm the effective temperatures of the two targets. We have use the COS Spectroscopy Target Acquisiton and COS Spectroscopy Exposure Time SImulators to determine our exposure times. Our targets do not exceed the brightness limits for COS, and are isolated with good coordinates. For target acquistion, we determined the time required to reach a signal to noise of at least 40. White dwarf stars are faint and can have high proper motions. GAIA has reduced this issue by determining many proper motions. However, to be safe, we will acquire our targets using ACQ/SEARCH, ACQ/PEAKXD, and ACQ/PEAKD. For our science observations, we have determined exposure times to achieve a S/N of 15-20 at a wavelngth of 1150 Angstroms for the G130M grating, and a S/N of 15-20 at 1500 Angstroms for the G160M and G140L gratings. The science observations will be done in TIME-TAG mode. This will enable us to search for any variability. Neither star is known to be a large amplitude variable. However, SDSSJ141127 is close to the suspected temperature for the initiation of gmode pulsations in helium atmosphere whtie dwarfs. The amplitudes of these possible pulsations is very small ( less than 1 ppt). ------------------------------------------------------------------------------------ 17186( 3) - 27-Sep-2022 17:11:50 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J170727 STAR, DB RA=17H07M27.1085S +/- 0.0853", J2000 V = 17.9 +/- 0.2 G=18.403 .10+203153.2 DEC=+20D31'53.27" +/- 0.0927" 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) 2000 2.342104434255327E-5 -0.007802000095580297 0.0015367 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J141127 STAR, DB RA=14H11M27.1130S +/- 0.1057", J2000 V = 16.8 +/- 0.2 u=16.7, g=16.95 .11+035429.6 DEC=+03D54'29.62" +/- 0.0707" 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) 2000 -0.0027284115839040384 0.007218 0.0032967 ------------------------------------------------------------------------------------------------------------------------------------ 17186( 3) - 27-Sep-2022 17:11:50 - [ 4] Visit: 01 (170727 1640) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J17072 COS/FUV ACQ/SEA PSA G160M 1589 CENTER=FLUX-WT, SCAN-SIZE=2, 1 6.0 S (6 7.10+203153 RCH SEGMENT=BOTH, STEP-SIZE=1.767 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J17072 COS/FUV ACQ/PEA PSA G160M 1589 SEGMENT=BOTH, CENTER=FLUX-WT, 1 6.0 S (6 7.10+203153 KXD NUM-POS=3, STEP-SIZE=1.3 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J17072 COS/FUV ACQ/PEA PSA G160M 1589 CENTER=FLUX-WT-FLR, NUM-POS=5, 1 6.0 S (6 7.10+203153 KD SEGMENT=BOTH, STEP-SIZE=0.9 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J17072 COS/FUV TIME-TA PSA G160M 1589 BUFFER-TIME=4255, 1 1000 S 7.10+203153 G SEGMENT=BOTH, FP-POS=ALL see below .2 (5913 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSS-J17072 COS/FUV TIME-TA PSA G140L 1280 SEGMENT=BOTH, 1 200 S (200 7.10+203153 G BUFFER-TIME=2789, FP-POS=1 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSS-J17072 COS/FUV TIME-TA PSA G140L 1280 FP-POS=2, SEGMENT=BOTH, 1 200 S 7.10+203153 G BUFFER-TIME=2789 see below .2 (335 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J170727.10+203 1 COS/FUV ACQ/SEA PSA G160M 1589 none none none none 1 N/A 153.2 RCH SDSS-J170727.10+203 2 COS/FUV ACQ/PEA PSA G160M 1589 none none none none 1 N/A 153.2 KXD SDSS-J170727.10+203 3 COS/FUV ACQ/PEA PSA G160M 1589 none none none none 1 N/A 153.2 KD SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G160M 1589 none none none 1 1 1969.0 S 153.2 G SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G160M 1589 none none none 2 2 N/A 153.2 G SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G160M 1589 none none none 3 2 1344.0 S 153.2 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G160M 1589 none none none 4 3 1600.0 S 153.2 G SDSS-J170727.10+203 5 COS/FUV TIME-TA PSA G140L 1280 none none none none 3 N/A 153.2 G SDSS-J170727.10+203 6 COS/FUV TIME-TA PSA G140L 1280 none none none none 3 335.0 S 153.2 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 6] Visit: 02 (17027 G130M) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J17072 COS/FUV ACQ/SEA PSA G130M 1291 CENTER=FLUX-WT, SCAN-SIZE=2, 1 2.5 S (2.5 7.10+203153 RCH SEGMENT=BOTH, STEP-SIZE=1.767 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J17072 COS/FUV ACQ/PEA PSA G130M 1291 SEGMENT=BOTH, NUM-POS=3, 1 2.5 S (2.5 7.10+203153 KXD STEP-SIZE=1.3, CENTER=FLUX-WT S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J17072 COS/FUV ACQ/PEA PSA G130M 1291 CENTER=FLUX-WT-FLR, NUM-POS=5, 1 2.5 S (2.5 7.10+203153 KD SEGMENT=BOTH, STEP-SIZE=0.9 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J17072 COS/FUV TIME-TA PSA G130M 1222 SEGMENT=BOTH, FP-POS=ALL, 1 525 S 7.10+203153 G BUFFER-TIME=2205 (2772 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSS-J17072 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=2736, FP-POS=ALL, 1 600 S 7.10+203153 G SEGMENT=BOTH (2625 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSS-J17072 COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=2729, 1 420 S (420 7.10+203153 G SEGMENT=BOTH, FP-POS=3 S) .2 ------------------------------------------------------------------------------------------------------------------------------------ 7 SDSS-J17072 COS/FUV TIME-TA PSA G140L 1280 SEGMENT=BOTH, 1 420 S 7.10+203153 G BUFFER-TIME=2729, FP-POS=4 see below .2 (533 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J170727.10+203 1 COS/FUV ACQ/SEA PSA G130M 1291 none none none none 1 N/A 153.2 RCH SDSS-J170727.10+203 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A 153.2 KXD SDSS-J170727.10+203 3 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A 153.2 KD SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G130M 1222 none none none 1 1 N/A 153.2 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G130M 1222 none none none 2 1 N/A 153.2 G SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G130M 1222 none none none 3 1 797.0 S 153.2 G SDSS-J170727.10+203 4 COS/FUV TIME-TA PSA G130M 1222 none none none 4 2 925.0 S 153.2 G SDSS-J170727.10+203 5 COS/FUV TIME-TA PSA G130M 1096 none none none 1 2 N/A 153.2 G SDSS-J170727.10+203 5 COS/FUV TIME-TA PSA G130M 1096 none none none 2 2 825.0 S 153.2 G SDSS-J170727.10+203 5 COS/FUV TIME-TA PSA G130M 1096 none none none 3 3 N/A 153.2 G SDSS-J170727.10+203 5 COS/FUV TIME-TA PSA G130M 1096 none none none 4 3 N/A 153.2 G SDSS-J170727.10+203 6 COS/FUV TIME-TA PSA G140L 1280 none none none none 3 N/A 153.2 G SDSS-J170727.10+203 7 COS/FUV TIME-TA PSA G140L 1280 none none none none 3 533.0 S 153.2 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 8] Visit: 03 (141127 G130 and G160) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J14112 COS/FUV ACQ/SEA PSA G130M 1291 CENTER=FLUX-WT, SCAN-SIZE=2, 1 2.0 S (2 7.11+035429 RCH SEGMENT=BOTH, STEP-SIZE=1.767 S) .6 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J14112 COS/FUV ACQ/PEA PSA G130M 1291 SEGMENT=BOTH, CENTER=FLUX-WT, 1 2.0 S (2 7.11+035429 KXD NUM-POS=3, STEP-SIZE=1.3 S) .6 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J14112 COS/FUV ACQ/PEA PSA G130M 1291 CENTER=FLUX-WT-FLR, 1 2.0 S (2 7.11+035429 KD SEGMENT=BOTH, NUM-POS=5.0, S) .6 STEP-SIZE=0.9 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J14112 COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=1141, FP-POS=ALL, 1 425 S 7.11+035429 G SEGMENT=BOTH (1685 S) .6 ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSS-J14112 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=1744, FP-POS=ALL, 1 225 S 7.11+035429 G SEGMENT=BOTH (1400 S) .6 ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSS-J14112 COS/FUV TIME-TA PSA G160M 1589 BUFFER-TIME=2096, FP-POS=ALL, 1 500 S 7.11+035429 G SEGMENT=BOTH see below .6 (2506 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J141127.11+035 1 COS/FUV ACQ/SEA PSA G130M 1291 none none none none 1 N/A 429.6 RCH SDSS-J141127.11+035 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A 429.6 KXD SDSS-J141127.11+035 3 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A 429.6 KD SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G130M 1222 none none none 1 1 N/A 429.6 G SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G130M 1222 none none none 2 1 N/A 429.6 G SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G130M 1222 none none none 3 1 N/A 429.6 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G130M 1222 none none none 4 1 410.0 S 429.6 G SDSS-J141127.11+035 5 COS/FUV TIME-TA PSA G130M 1096 none none none 1 2 N/A 429.6 G SDSS-J141127.11+035 5 COS/FUV TIME-TA PSA G130M 1096 none none none 2 2 N/A 429.6 G SDSS-J141127.11+035 5 COS/FUV TIME-TA PSA G130M 1096 none none none 3 2 425.0 S 429.6 G SDSS-J141127.11+035 5 COS/FUV TIME-TA PSA G130M 1096 none none none 4 2 525.0 S 429.6 G SDSS-J141127.11+035 6 COS/FUV TIME-TA PSA G160M 1589 none none none 1 2 538.0 S 429.6 G SDSS-J141127.11+035 6 COS/FUV TIME-TA PSA G160M 1589 none none none 2 3 N/A 429.6 G SDSS-J141127.11+035 6 COS/FUV TIME-TA PSA G160M 1589 none none none 3 3 N/A 429.6 G SDSS-J141127.11+035 6 COS/FUV TIME-TA PSA G160M 1589 none none none 4 3 968.0 S 429.6 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 10] Visit: 04 (141127 G140L) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J14112 COS/FUV ACQ/SEA PSA G140L 1280 CENTER=FLUX-WT, SCAN-SIZE=2, 1 6 S (6 S) 7.11+035429 RCH SEGMENT=BOTH, STEP-SIZE=1.767 .6 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J14112 COS/FUV ACQ/PEA PSA G140L 1280 CENTER=FLUX-WT, SEGMENT=BOTH, 1 6 S (6 S) 7.11+035429 KXD NUM-POS=3, STEP-SIZE=1.3 .6 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J14112 COS/FUV ACQ/PEA PSA G140L 1280 CENTER=FLUX-WT-FLR, NUM-POS=5, 1 6 S (6 S) 7.11+035429 KD SEGMENT=BOTH, STEP-SIZE=0.9 .6 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J14112 COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=1458, FP-POS=ALL, 1 450 S 7.11+035429 G SEGMENT=BOTH see below .6 (1696 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J141127.11+035 1 COS/FUV ACQ/SEA PSA G140L 1280 none none none none 1 N/A 429.6 RCH SDSS-J141127.11+035 2 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A 429.6 KXD SDSS-J141127.11+035 3 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A 429.6 KD SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G140L 1280 none none none 1 1 432.0 S 429.6 G SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G140L 1280 none none none 2 1 432.0 S 429.6 G SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G140L 1280 none none none 3 1 432.0 S 429.6 G SDSS-J141127.11+035 4 COS/FUV TIME-TA PSA G140L 1280 none none none 4 1 400.0 S 429.6 G 17186( 3) - 27-Sep-2022 17:11:50 - [ 11] Summary Form for Proposal 17186 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAKD, ACQ/PEAKXD, ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1141, BUFFER-TIME=1458, BUFFER-TIME=1744, BUFFER-TIME=2096, BUFFER-TIME=2205, BUFFER-TIME=2729, BUFFER-TIME=2736, BUFFER-TIME=2789, BUFFER-TIME=4255, CENTER=FLUX-WT, CENTER=FLUX-WT-FLR, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, FP-POS=ALL, NUM-POS=3, NUM-POS=5, NUM-POS=5.0, SCAN-SIZE=2, SEGMENT=BOTH, STEP-SIZE=0.9, STEP-SIZE=1.3, STEP-SIZE=1.767 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G140L, G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSS-J141127.11+035429.6, SDSS-J170727.10+203153.2 ------------------------------------------------------------------------------------------------------------------------------------