14491( 5) - 02-May-2016 18:13:58 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14491 Version: 5 Check-in Time: 02-May-2016 18:13:58 STScI Edit Number: 1 Title Trojan Binary Candidate: A Slow-Rotating Mission Target ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Keith S. Noll NASA Goddard Space Flight Center Y CoI: Dr. Harold F. Levison Southwest Research Institute N CoI: Dr. William M. Grundy Lowell Observatory N CoI: Dr. Marc W. Buie Southwest Research Institute N ------------------------------------------------------------------------------------ Abstract A mission to the unexplored Jupiter Trojans is explicitly called for in the Planetary Decadal and HST observations in early 2016 can influence mission plans for both Discovery and New Frontiers. We propose to observe a Trojan that will be targeted by the step-1 Discovery mission, Lucy. (11351) 1997 TS25 is a Trojan that is notable for having one of the longest known rotation periods of any small body, T=514 h. A possible cause for this long period would be the existence of a tidally locked binary similar to the already-known long-period binary Trojan, (617) Patroclus. If so, the components will be separated by ~0.18 arcsec at lightcurve maximum, resolvable by WFC3. We will coordinate with groundbased observations to schedule near a maximum and thus require only a single orbit to confidently test whether (11351) 1997 TS25 is binary. Binary Trojans offer scientific benefits beyond the impact to any specific mission. Orbit-derived mass and density can be used to constrain planetary migration models. Low density is characteristic of bodies found in the dynamically cold Kuiper Belt, a remnant of the solar system's protoplanetary disk. Only one undisputed density has been measured in the Trojans, that of the binary (617) Patroclus, which has a low density of 0.8 g/cm3, similar to the low densities found in the Kuiper Belt. Evidence for or against a possible common origin linking Trojans and KBOs is a key constraint for planetesimal formation and planetary migration models relevant to the solar system and to planetary systems in general. ------------------------------------------------------------------------------------ Observations Description ------------------------ Single orbit visit to Trojan (11351) Leucus (temp id 1997 TS25). Standard WFC3 imaging. The timing is tied to ground-based lightcurve analysis being completed by co-I Buie. One full phase completed, waiting for second repeating phase to take visit off hold. Preliminary guess to phase included in initial phase 2 submission. ------------------------------------------------------------------------------------ 14491( 5) - 02-May-2016 18:13:58 - [ 2] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: TROJAN11351 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Trojan ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=5.259886569144591, E=.06547811318672574, I=11.57174016291844, O=251.1003040760594, W=159.1547220321686, M=13.33041690556806, EQUINOX=J2000, EPOCH=08-DEC-2009:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 18.2 +/- 0.4 Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ 14491( 5) - 02-May-2016 18:13:58 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14491( 5) - 02-May-2016 18:13:58 - [ 4] Visit: 01 Visit Requirements: BETWEEN 08-JUN-2016:12:36 AND 10-JUN-2016:16:12; BETWEEN 17-JUN-2016:15:48 AND 19-JUN-2016:19:25; BETWEEN 27-JUN-2016:03:01 AND 28-JUN-2016:22:37; BETWEEN 06-JUL-2016:06:14 AND 08-JUL-2016:00:49 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 TROJAN11351 WFC3/UVI ACCUM UVIS2-C51 F555W FLASH=12 1 20 S (80 GS ACQ SCENARIO BASE1B3; S 2C-SUB S) PATTERN 1 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 2 TROJAN11351 WFC3/UVI ACCUM UVIS2-C51 F438W FLASH=12 1 60 S (240 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TROJAN11351 WFC3/UVI ACCUM UVIS2-C51 F814W FLASH=12 1 30 S (120 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TROJAN11351 WFC3/UVI ACCUM UVIS2-C51 F336W FLASH=12 1 120 S (480 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 TROJAN11351 WFC3/UVI ACCUM UVIS2-C51 F555W FLASH=11 2 100 S (200 S 2C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ TROJAN11351 1 WFC3/UVI ACCUM UVIS2-C5 F555W 1 none none none 1 N/A S 12C-SUB TROJAN11351 1 WFC3/UVI ACCUM UVIS2-C5 F555W 2 none none none 1 N/A S 12C-SUB TROJAN11351 1 WFC3/UVI ACCUM UVIS2-C5 F555W 3 none none none 1 N/A S 12C-SUB TROJAN11351 1 WFC3/UVI ACCUM UVIS2-C5 F555W 4 none none none 1 N/A S 12C-SUB TROJAN11351 2 WFC3/UVI ACCUM UVIS2-C5 F438W 1 none none none 1 N/A S 12C-SUB TROJAN11351 2 WFC3/UVI ACCUM UVIS2-C5 F438W 2 none none none 1 N/A S 12C-SUB TROJAN11351 2 WFC3/UVI ACCUM UVIS2-C5 F438W 3 none none none 1 N/A S 12C-SUB TROJAN11351 2 WFC3/UVI ACCUM UVIS2-C5 F438W 4 none none none 1 N/A S 12C-SUB TROJAN11351 3 WFC3/UVI ACCUM UVIS2-C5 F814W 1 none none none 1 N/A S 12C-SUB 14491( 5) - 02-May-2016 18:13:58 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ TROJAN11351 3 WFC3/UVI ACCUM UVIS2-C5 F814W 2 none none none 1 N/A S 12C-SUB TROJAN11351 3 WFC3/UVI ACCUM UVIS2-C5 F814W 3 none none none 1 N/A S 12C-SUB TROJAN11351 3 WFC3/UVI ACCUM UVIS2-C5 F814W 4 none none none 1 N/A S 12C-SUB TROJAN11351 4 WFC3/UVI ACCUM UVIS2-C5 F336W 1 none none none 1 N/A S 12C-SUB TROJAN11351 4 WFC3/UVI ACCUM UVIS2-C5 F336W 2 none none none 1 N/A S 12C-SUB TROJAN11351 4 WFC3/UVI ACCUM UVIS2-C5 F336W 3 none none none 1 N/A S 12C-SUB TROJAN11351 4 WFC3/UVI ACCUM UVIS2-C5 F336W 4 none none none 1 N/A S 12C-SUB TROJAN11351 5 WFC3/UVI ACCUM UVIS2-C5 F555W none none 1 none 1 N/A S 12C-SUB TROJAN11351 5 WFC3/UVI ACCUM UVIS2-C5 F555W none none 2 none 1 N/A S 12C-SUB 14491( 5) - 02-May-2016 18:13:58 - [ 6] Summary Form for Proposal 14491 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=11, FLASH=12 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 06-JUL-2016:06:14 AND 08-JUL-2016:00:49, BETWEEN 08-JUN-2016:12:36 AND 10-JUN-2016:16:12, BETWEEN 17-JUN-2016:15:48 AND 19-JUN-2016:19:25, BETWEEN 27-JUN-2016:03:01 AND 28-JUN-2016:22:37, GS ACQ SCENARIO BASE1B3, PATTERN 1 1-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W, F438W, F555W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names TROJAN11351 ------------------------------------------------------------------------------------------------------------------------------------