15147( 5) - 27-Feb-2018 16:16:04 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15147 Version: 5 Check-in Time: 27-Feb-2018 16:16:04 STScI Edit Number: 3 Title Extreme Doppler Shifting of Io's Neutral Jets ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Carl Schmidt Boston University Y CoI: Dr. Lorenz Roth Royal Institute of Technology N CoI: Dr. Kurt David Retherford Southwest Research Institute N CoI: Dr. Nickolay Ivchenko Royal Institute of Technology N CoI: Dr. Joachim Saur Universitat zu Koeln N ------------------------------------------------------------------------------------ Abstract The dynamics and the extension of Jupiter's magnetosphere are determined by the massive internal plasma sources combined with the fast rotation. The vast majority of the plasma originates from the atmosphere of the moon Io, the most volcanically active body in our solar system. Here we propose to characterize the density and velocity of energetic neutral atoms escaping from Io's atmosphere. Exploiting the high resolution and sensitivity of the COS G130M spectral mode, we will measure the Doppler velocities of atomic O, S and Cl streams, which are energized through charge exchange and dissociative recombination of molecular ions. Prior COS observations of Io revealed a large number of emission lines from several ion and neutral species with excellent S/N, obtained over a single HST orbit. Those spectra were obtained surrounding eclipse geometry, where Doppler shifts are minimized and were restricted to Io itself rather than the stream region. Here we will target the extended clouds with only two orbits total when the moon is at eastern and western elongation for maximum Doppler shifts. The observations will provide new constraints on the diffuse large-scale cloud structures in the Jovian system and significantly improve our understanding of the transport of mass and energy within the Io-torus interaction. The absolute brightness, in combination with plasma parameters from line ratios/collision strengths, will allow us to quantify the outflow of energetic neutral atoms from Io's main sulfur-oxygen atmosphere for the first time. ------------------------------------------------------------------------------------ Observations Description ------------------------ Science goals necessitate a very restrictive time windows for these observations. One HST visit will be made for Io's elongation on each side of Jupiter. Precise centering is not required, so the observations utilize only acquire/search to reduce overhead. For each, spectra on and off of Io's disk will be compared. The COS aperture is to be pointed just off of Io's disk in the anti-jovian direction. This must occur during times when Io is just prior to its maximum elongation from Jupiter as seen from the Earth, where both Doppler shift and column density are maximized. Additionally, timing requires the sub-Io System III longitude of Jupiter to be in the 90-145 degree range, where the interaction between Io and the plasma torus is the greatest. Lastly, the orientation restriction is specified to align the long axis of the neutral jets (the Jovian magnetic equator) as close as possible to the COS 15147( 5) - 27-Feb-2018 16:16:04 - [ 2] cross-dispersion axis, thereby maximizing the effective spectral resolution. Visits while Io is visible from the southwestern US observatories (Large Binocular Telescope, Discovery Channel Telescope) are preferred, but not critical. ------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: IO-LEADING ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE-IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF IO-LEADING JUPITER FROM EARTH GT 30", SEP OF IO-LEADING CALLISTO FROM EARTH GT 10", SEP OF IO-LEADING EUROPA FROM EARTH GT 10", SEP OF IO-LEADING GANYMEDE FROM EARTH GT 10" ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5.25 +/- 0.35 Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 TARGET NAME: IO-OFFSET-LEADING ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS TYPE=POS_ANGLE, RAD=2.0, ANG=106.72, REF=NORTH SEP OF IO-OFFSET-LEADING JUPITER FROM EARTH GT 30", SEP OF IO-OFFSET-LEADING CALLISTO FROM EARTH GT 10", SEP OF IO-OFFSET-LEADING EUROPA FROM EARTH GT 10", SEP OF IO-OFFSET-LEADING GANYMEDE FROM EARTH GT 10", OLG OF IO FROM EARTH BETWEEN 75.0 90.0, R_VEL IO EARTH LT -17.0, SEP OF IO-OFFSET-LEADING SUN FROM EARTH GT 130.0D, CML OF JUPITER FROM IO BETWEEN 90 145 ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5.25 This offest is intended to point further east when Io is at its eastern (leading) elongation from Jupiter. Position angle is specied as Io's North Pole Position Ephemeris Center: EARTH Angle (NPPA) + 90 degrees. At opposition, both Io and Acquisition Uncertainty: 0.1 " Jupiter's 's NPPA is 16.7 deg and its few degree change Extended: YES over the allowable observing windows is negligible. The offset radius places the limb of Io's disk 0.2" outside the 2.5" COS PSA at opposition. The most critical restriction on observing windows in Io's orbital longitude, since this maximizes both column density and Doppler shift. The oxygen lines to be observed are also present in terrestrial airglow. To minimize this terrestrial contribution, we choose to observe near opposition to maximize time in Earth's shadow, and at high Doppler blueshift to best seperate the oxygen line spread functions of each component. Lastly, Io must be near the torus' centrifugal equator to maximize the density driving emissions. Therefore, the sub-Io Jupiter System III longitude should be between 90 and 145 degrees. ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 5] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 TARGET NAME: IO-TRAILING ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE-IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF IO-TRAILING JUPITER FROM EARTH GT 30", SEP OF IO-TRAILING CALLISTO FROM EARTH GT 10", SEP OF IO-TRAILING EUROPA FROM EARTH GT 10", SEP OF IO-TRAILING GANYMEDE FROM EARTH GT 10" ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5.25 Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 6] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 TARGET NAME: IO-OFFSET-TRAILING ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS TYPE=POS_ANGLE, RAD=2.0, ANG=286.72, REF=NORTH SEP OF IO-OFFSET-TRAILING JUPITER FROM EARTH GT 30", SEP OF IO-OFFSET-TRAILING CALLISTO FROM EARTH GT 10", SEP OF IO-OFFSET-TRAILING EUROPA FROM EARTH GT 10", SEP OF IO-OFFSET-TRAILING GANYMEDE FROM EARTH GT 10", OLG OF IO FROM EARTH BETWEEN 255.0 270.0, R_VEL IO EARTH GT 17.0, SEP OF IO-OFFSET-TRAILING SUN FROM EARTH GT 130.0D, CML OF JUPITER FROM IO BETWEEN 90 145 ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5.25 This offest is intended to point further west when Io is at its western elongation from Jupiter. Position angle is specied as Io's North Pole Position Angle (NPPA) + 270 Ephemeris Center: EARTH degrees. At opposition, both Io and Jupiter's 's NPPA is Extended: YES 16.7 deg and its few degree change over the allowable observing windows is negligible. The offset radius places the limb of Io's disk 0.2" outside the 2.5" COS PSA at opposition. The most critical restriction on observing windows in Io's orbital longitude, since this maximizes both column density and relative velocity needed for primary science goals. The oxygen lines to be observed are also present in terrestrial airglow. To minimize this terrestrial contribution, we choose to observe near opposition to maximize time in Earth's shadow, and at high Doppler redshift to best seperate the oxygen line spread functions of each component. Lastly, Io must be near the torus' centrifugal equator to maximize the density driving emissions. Therefore, the sub-Io Jupiter System III longitude should be between 90 and 145 degrees. ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 7] Visit: 01 (Leading) Visit Requirements: ORIENT 218D TO 264 D On Hold Comments: Additional Comments: Ideal ORIENT angle is 241 or 61 degrees and the margin is here chosen for schedulability. Aligning the long-axis of the neutral jets with COS the cross-dispersion Y axis will maximize the effective spectral resolution. This occurs at ORIENT 61 and 241 degrees and an orientation as close as possible to either value are requested. (Jovian North is 16 degrees east of Celestial North, so the leading side jet is aligned to a position angle of ~106. degrees. COS has V3 = Y - 45 = 61). 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 IO-LEADING COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, 1 1 S (1 S) GS ACQ SCENARIO BASE1B3 RCH CENTER=FLUX-WT-FLR Comments: Io's surface brightness uploaded to the COS ETC. We calculate this using the Earth-Sun-Io geometry, the disk-averaged geometric albedos from Feaga et al. (2004 FUV), Clarke et al. (1994 JGR Fig 7b) and Tsang et al. (2013) in the NUV, and Nelson et al. (1996 Fig 1b, Visibile), and the NRL solar irradiance http://lasp.colorado.edu/lisird/nrlssi/ near solar maximium. COS.sa.1010061 ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-LEADING COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=1000, 1 250 S G SEGMENT=BOTH, LIFETIME-POS=LP4 see below (249 S) Comments: Io spectrum in the ETC is the same as previous. COS.sp.1010060 gives buffer time =2/3*8, 614 s. We choose 1000s to allow plenty of margin for bright emissions near the ansae of the plasma torus. ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-OFFSET-L COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=1000, FP-POS=4, 1 1341 S GS ACQ SCENARIO BASE1B3 EADING G SEGMENT=BOTH, LIFETIME-POS=LP4 (1341 S) Comments: Io spectrum in the ETC is the same as previous. COS.sp.1010060 gives buffer time =2/3*8, 614 s. We choose 1000s to allow plenty of margin for bright emissions near the ansae of the plasma torus. ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK COS/NUV TIME-TA DEF DEF BUFFER-TIME=80 1 4 S (4 S) G ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ IO-LEADING 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH IO-LEADING 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 249.0 S G IO-OFFSET-LEADING 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G DARK 4 COS/NUV TIME-TA DEF DEF none none none none 1 N/A G 15147( 5) - 27-Feb-2018 16:16:04 - [ 9] Visit: 02 (Trailing) Visit Requirements: ORIENT 35D TO 89 D On Hold Comments: Additional Comments: Ideal ORIENT angle is 62 or 242 and the margin is here chosen for schedulability. Aligning the long-axis of the neutral jets with COS the cross-dispersion Y axis will maximize the effective spectral resolution. This occurs at ORIENT 62 and 242 degrees, so orientations as close as possible to either value are requested. (Jovian North is 16 deg east of Celestial North, so the trailing side jet is aligned to a position angle of ~287. degrees. COS has V3 = Y - 45 = 242). 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 IO-TRAILING COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, 1 1 S (1 S) GS ACQ SCENARIO BASE1B3 RCH CENTER=FLUX-WT-FLR Comments: Io's surface brightness uploaded to the COS ETC. We calculate this using the Earth-Sun-Io geometry, the disk-averaged geometric albedos from Feaga et al. (2004 FUV), Clarke et al. (1994 JGR Fig 7b) and Tsang et al. (2013) in the NUV, and Nelson et al. (1996 Fig 1b, Visibile), and the NRL solar irradiance http://lasp.colorado.edu/lisird/nrlssi/ near solar maximium. COS.sa.1010061 ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-TRAILING COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=1000, FP-POS=3, 1 250 S (250 G SEGMENT=BOTH, LIFETIME-POS=LP4 S) Comments: Io spectrum in the ETC is the same as previous. COS.sp.1010059 gives buffer time =2/3*8, 614 s. We choose 1000s to allow plenty of margin for bright emissions near the ansae of the plasma torus. ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-OFFSET-T COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=1000, FP-POS=4, 1 1320 S GS ACQ SCENARIO BASE1B3 RAILING G SEGMENT=BOTH, LIFETIME-POS=LP4 (1320 S) Comments: Io spectrum in the ETC is the same as previous. COS.sp.1010059 gives buffer time =2/3*8, 614 s. We choose 1000s to allow plenty of margin for bright emissions near the ansae of the plasma torus. ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK COS/NUV TIME-TA DEF DEF BUFFER-TIME=80 1 4 S (4 S) G ------------------------------------------------------------------------------------------------------------------------------------ 15147( 5) - 27-Feb-2018 16:16:04 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ IO-TRAILING 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH IO-TRAILING 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G IO-OFFSET-TRAILING 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G DARK 4 COS/NUV TIME-TA DEF DEF none none none none 1 N/A G 15147( 5) - 27-Feb-2018 16:16:04 - [ 11] Summary Form for Proposal 15147 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures DEF, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1000, BUFFER-TIME=80, CENTER=FLUX-WT-FLR, FP-POS=3, FP-POS=4, LIFETIME-POS=LP4, SCAN-SIZE=3, SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, ORIENT 218D TO 264 D, ORIENT 35D TO 89 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements DEF, G130M, G230L ------------------------------------------------------------------------------------------------------------------------------------ Target Names DARK, IO-LEADING, IO-OFFSET-LEADING, IO-OFFSET-TRAILING, IO-TRAILING ------------------------------------------------------------------------------------------------------------------------------------