17525( 16) - 01-Aug-2024 18:54:18 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17525 Version: 16 Check-in Time: 01-Aug-2024 18:54:18 STScI Edit Number: 7 Title Improving the Orbit of Queta: Enabling Observations with the Lucy Spacecraft ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Keith S. Noll NASA Goddard Space Flight Center Y CoI: Dr. Michael E Brown California Institute of Technology N CoI: Dr. Harold F. Levison Southwest Research Institute N CoI: Dr. Marc W. Buie Southwest Research Institute N ------------------------------------------------------------------------------------ Abstract (3548) Eurybates will be the first Trojan asteroid to be explored in situ when the Lucy spacecraft flies by it in August 2027. The possibility of close-up study of Eurybates' satellite, Queta, offers a unique opportunity to test whether Eurybates' unusual properties are tied to its collisional history and, more broadly, how collisional evolution shapes small body populations. It is critical to reduce the orbital uncertainty and improve knowledge of the relative position of Queta as soon as possible to enable planning for the best angular resolution and lighting conditions in the brief window when spacecraft observations can be made. With a single orbit we can reduce the positional uncertainty for Queta by almost a factor of two - which translates to a roughly equivalent gain in resolution for observations with a given angular coverage. As a secondary objective, we will collect astrometric information from trailed stars in the full UVIS aperture to improve predictions for future stellar occultations. HST is required because Queta is 8.7 magnitudes fainter than Eurybates and will be observed at a separation of approximately 0.5 arcsec - an observational regime that is unique to Hubble. ------------------------------------------------------------------------------------ Observations Description ------------------------ Single orbit observation timed to occur when Eurybates' satellite Queta is more than 0.4 arcsec from Eurybates but is also away from elongation. This geometry gives the best discrimination between different possible orbits and hence the most improvement in knowledge of the orbit, in particular, the orbital period. The window is selected to meet this requirement. ------------------------------------------------------------------------------------ 17525( 16) - 01-Aug-2024 18:54:18 - [ 2] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: EURYBATES ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Trojan asteroid with a satellite ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=5.194825660909952, E=0.08892019463262771, I=8.05897310596958 , O=43.53959194136358, W=27.42986950746389, M=279.393486820639, EQUINOX=J2000, EPOCH=05-AUG-2019:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 23 +/- 0.3 V-mag is expected brightness of the satellite. Eurybates is 8.5 mags brighter and will saturate. This is expected and consistent with previous observations that have Ephemeris Center: EARTH successfully recovered the faint satellite. ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 TARGET NAME: EURYBATES-COPY ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Trojan asteroid with a satellite ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=5.194825660909952, E=0.08892019463262771, I=8.05897310596958 , O=43.53959194136358, W=27.42986950746389, M=279.393486820639, EQUINOX=J2000, EPOCH=05-AUG-2019:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 23 +/- 0.3 V-mag is expected brightness of the satellite. Eurybates is 8.5 mags brighter and will saturate. This is expected and consistent with previous observations that have Ephemeris Center: EARTH successfully recovered the faint satellite. ------------------------------------------------------------------------------------------------------------------------------------ 17525( 16) - 01-Aug-2024 18:54:18 - [ 3] Visit: 01 Visit Requirements: BETWEEN 27-JAN-2024:00:00:00 AND 27-JAN-2024:22:00:00; BETWEEN 13-FEB-2024:00:00:00 AND 14-FEB-2024:12:00:00; BETWEEN 28-JAN-2024:01:00:00 AND 28-JAN-2024:06:00:00; BETWEEN 05-MAR-2024:00:00:00 AND 06-MAR-2024:12:00:00; VISIBILITY INTERVAL NO GYRO BIAS UPDATE ON MOVING TARGET 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 EURYBATES WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 SEQ 1-5 NON-INT S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 EURYBATES WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.1719, 0.1837 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 EURYBATES WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.3437, 0.3674 S S) ------------------------------------------------------------------------------------------------------------------------------------ 4 EURYBATES WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.4760, 0.5286 S S) ------------------------------------------------------------------------------------------------------------------------------------ 5 EURYBATES WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.6544, 0.6796 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ EURYBATES 1 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES 2 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES 3 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES 4 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES 5 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S 17525( 16) - 01-Aug-2024 18:54:18 - [ 4] Visit: 51 Visit Requirements: BETWEEN 04-MAY-2024:19:30:00 AND 04-MAY-2024:23:59:59; BETWEEN 05-MAY-2024:03:00:00 AND 05-MAY-2024:12:00:00; BETWEEN 04-MAY-2024:13:30:00 AND 04-MAY-2024:18:00:00; BETWEEN 02-MAY-2024:00:00:00 AND 03-MAY-2024:00:00:00; BETWEEN 27-MAY-2024:06:00:00 AND 28-MAY-2024:02:00:00; BETWEEN 28-MAY-2024:09:00:00 AND 28-MAY-2024:23:59:00; BETWEEN 22-JAN-2025:12:00:00 AND 23-JAN-2025:18:00:00; BETWEEN 07-FEB-2025:06:00:00 AND 08-FEB-2025:12:00:00; BETWEEN 02-MAR-2025:12:00:00 AND 03-MAR-2025:18:00:00; VISIBILITY INTERVAL NO GYRO BIAS UPDATE ON MOVING TARGET 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 EURYBATES-C WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 SEQ 1-5 NON-INT OPY S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 EURYBATES-C WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.1719, 0.1837 OPY S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 EURYBATES-C WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.3437, 0.3674 OPY S S) ------------------------------------------------------------------------------------------------------------------------------------ 4 EURYBATES-C WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.4760, 0.5286 OPY S S) ------------------------------------------------------------------------------------------------------------------------------------ 5 EURYBATES-C WFC3/UVI ACCUM UVIS2 F350LP 1 370 S (370 POS TARG 0.6544, 0.6796 OPY S 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 | ------------------------------------------------------------------------------------------------------------------------------------ EURYBATES-COPY 1 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES-COPY 2 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES-COPY 3 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES-COPY 4 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S EURYBATES-COPY 5 WFC3/UVI ACCUM UVIS2 F350LP none none none none 1 N/A S 17525( 16) - 01-Aug-2024 18:54:18 - [ 5] Summary Form for Proposal 17525 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 02-MAR-2025:12:00:00 AND 03-MAR-2025:18:00:00, BETWEEN 02-MAY-2024:00:00:00 AND 03-MAY-2024:00:00:00, BETWEEN 04-MAY-2024:13:30:00 AND 04-MAY-2024:18:00:00, BETWEEN 04-MAY-2024:19:30:00 AND 04-MAY-2024:23:59:59, BETWEEN 05-MAR-2024:00:00:00 AND 06-MAR-2024:12:00:00, BETWEEN 05-MAY-2024:03:00:00 AND 05-MAY-2024:12:00:00, BETWEEN 07-FEB-2025:06:00:00 AND 08-FEB-2025:12:00:00, BETWEEN 13-FEB-2024:00:00:00 AND 14-FEB-2024:12:00:00, BETWEEN 22-JAN-2025:12:00:00 AND 23-JAN-2025:18:00:00, BETWEEN 27-JAN-2024:00:00:00 AND 27-JAN-2024:22:00:00, BETWEEN 27-MAY-2024:06:00:00 AND 28-MAY-2024:02:00:00, BETWEEN 28-JAN-2024:01:00:00 AND 28-JAN-2024:06:00:00, BETWEEN 28-MAY-2024:09:00:00 AND 28-MAY-2024:23:59:00, POS TARG 0.1719, 0.1837, POS TARG 0.3437, 0.3674, POS TARG 0.4760, 0.5286, POS TARG 0.6544, 0.6796, SEQ 1-5 NON-INT, VISIBILITY INTERVAL NO GYRO BIAS UPDATE ON MOVING TARGET ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names EURYBATES, EURYBATES-COPY ------------------------------------------------------------------------------------------------------------------------------------