11969( 7) - 06-Jan-2009 17:59:29 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11969 Version: 7 Check-in Time: 06-Jan-2009 17:59:29 STScI Edit Number: 4 Title Satellite Search for Dawn Mission Targets, Vesta and Ceres ------------------------------------------------------------------------------------ Type Cycle GO/DD 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jian-Yang Li University of Maryland CoI: Dr. Lucy-Ann McFadden University of Maryland N CoI: Mr. Max Mutchler Space Telescope Science Institute Y CoI: Dr. Stefano Mottola DLR N ------------------------------------------------------------------------------------ Abstract We propose to carry out a dedicated satellite search program for asteroids Vesta and Ceres. Despite being the two largest asteroids, and having clear evidence of a violent collisional history for Vesta, Vesta and Ceres do not have any satellites found so far, neither have there been any dedicated satellite search program for them reported. We propose to take short and long exposure mosaics to cover the whole Hill sphere while using specific observing strategies and image processing techniques to search in close to the center body. In addition to its significant scientific merit, this proposed project will be important for the planning of NASA's Dawn mission. Currently Ceres is moving close to the Earth, making it more difficuilt to cover the whole stability region of satellites with minimal HST orbit requirement. Similar geometry will not repeat until the second half of 2009. Therefore we request DD time. ------------------------------------------------------------------------------------ Observations Description ------------------------ Vesta will not have the visibility to be scheduled until late 2009. Therefore we plan all 4 approved orbits for Ceres. We emphasize searching deep to both cover the whole Hill shpere of Ceres, and as close to Ceres as possible. Four one-orbit visits are planned for this purpose. The four visits are grouped into two two-visit groups, separated by one day. And each visit has one orbit. In the first group, we will put Ceres near the apex in each of the four WFPC2 CCD chips, and take long exposures to search faint objects around Ceres. Also, short, unsaturated, exposures with Ceres at the center of PC1 chip will be taken to be stacked together to model the PSF. In the second group, we will repeat the exposures for near apex pointing of Ceres, but replace the PC1 centered exposures with a four pointing mosaics, taking long exposures, to search for faint objects in a large region around Ceres. In order to avoid potential problem of moving objects tracking, we put together the pointings that are almost along a straightline into one one-orbit visit in each group. Out detailed observing plan is: Group 1: Visit 1, total 17 exposures: PC1 near-apex pointing, 1 short, 3 intermediate, 2 long 11969( 7) - 06-Jan-2009 17:59:29 - [ 2] WF3 near-apex pointing, 1 short, 3 intermediate, 2 long PC1 center pointing, 5 short Visit 2, total 17 exposures: WF2 near-apex pointing, 1 short, 3 intermediate, 2 long WF4 near-apex pointing, 1 short, 3 intermediate, 2 long PC1 center pointer, 5 short Group 2, 1 day after the first group: Visit 3, total 16 exposures: PC1 with Ceres (30", 30") from apex, 1 short, 2 long PC1 near-apex pointing, 1 short, 2 intermediate, 2 long WF3 near-apex pointing, 1 short, 2 intermediate, 2 long WF3 with Ceres (50", 50") from apex, 1 short, 2 long Visit 4, total 16 exposures: WF2 with Ceres (50", 50") from apex, 1 short, 2 long WF2 near-apex pointing, 1 short, 2 intermediate, 2 long WF4 near-apex pointing, 1 short, 2 intermediate, 2 long WF4 with Ceres (50", 50") from apex, 1 short, 2 long We will use F606W filter for all exposures. For WF chips, short exposure is 0.12 sec, intermediate 20 sec, and long 40 sec. For PC1 chips, short exposure is 0.6 sec, long exposure 40 sec. Two visits in each group should be scheduled together (Separation < 2 orbits). Two groups should be scheduled one day apart. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11969( 7) - 06-Jan-2009 17:59:29 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: CERES ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Asteroid 1 Ceres ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=2.766791532351548, E=.07947462245028122, I=10.58571555748677, O=80.40447317892902, W=72.89568694749072, M=344.5452233474741, EQUINOX=J2000, EPOCH=30-NOV-2008:00:00:00 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 7.94 +/- 0.11 Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ 11969( 7) - 06-Jan-2009 17:59:29 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type LINE Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 25 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 45 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type LINE Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 25 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 315 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 11969( 7) - 06-Jan-2009 17:59:29 - [ 5] Visit: 01 Visit Requirements: SEQ 01, 02 WITHIN 2.2 Orbits 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 CERES WFPC2 IMAGE WF3-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG 30, 30; GS ACQ SCENARIO BASE1T3; SEQ 1-4 NON-INT; PATTERN 3 1-3 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 2 CERES WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES 3 20 S POS TARG 30, 30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 CERES WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES 2 40 S POS TARG 30, 30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 4 CERES WFPC2 IMAGE PC1-FIX F606W ATD-GAIN=15 5 0.6 S Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 1 WFPC2 IMAGE WF3-FIX F606W 1 none none none 1 N/A CERES 1 WFPC2 IMAGE WF3-FIX F606W 2 none none none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 1 none 1 none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 1 none 2 none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 1 none 3 none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 2 none 1 none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 2 none 2 none 1 N/A CERES 2 WFPC2 IMAGE WF3-FIX F606W 2 none 3 none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 1 none 1 none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 1 none 2 none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 2 none 1 none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 2 none 2 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 1 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 2 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 3 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 4 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 5 none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 6] Visit: 02 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CERES WFPC2 IMAGE WF2-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG 30, -30; GS ACQ SCENARIO BASE1T3; SEQ 1-4 NON-INT; PATTERN 4 1-3 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 2 CERES WFPC2 IMAGE WF2-FIX F606W CLOCKS=YES 3 20 S POS TARG 30, -30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 CERES WFPC2 IMAGE WF2-FIX F606W CLOCKS=YES 2 40 S POS TARG 30, -30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 4 CERES WFPC2 IMAGE PC1-FIX F606W ATD-GAIN=15 5 0.6 S Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 1 WFPC2 IMAGE WF2-FIX F606W 1 none none none 1 N/A CERES 1 WFPC2 IMAGE WF2-FIX F606W 2 none none none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 1 none 1 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 1 none 2 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 1 none 3 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 2 none 1 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 2 none 2 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W 2 none 3 none 1 N/A CERES 3 WFPC2 IMAGE WF2-FIX F606W 1 none 1 none 1 N/A CERES 3 WFPC2 IMAGE WF2-FIX F606W 1 none 2 none 1 N/A CERES 3 WFPC2 IMAGE WF2-FIX F606W 2 none 1 none 1 N/A CERES 3 WFPC2 IMAGE WF2-FIX F606W 2 none 2 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 1 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 2 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 3 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 4 none 1 N/A CERES 4 WFPC2 IMAGE PC1-FIX F606W none none 5 none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 7] Visit: 03 Visit Requirements: AFTER 02 BY .9 D TO 1.1 D; SEQ 03, 04 WITHIN 2.2 Orbits 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 CERES WFPC2 IMAGE PC1 F606W ATD-GAIN=15 1 0.6 S POS TARG 12, 12; GS ACQ SCENARIO BASE1T3; SEQ 1-7 NON-INT Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 2 CERES WFPC2 IMAGE PC1 F606W CLOCKS=YES 2 40 S SAME POS AS 1 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 CERES WFPC2 IMAGE WF3-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG 30, 30; PATTERN 3 3-5 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 4 CERES WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES 2 20 S POS TARG 30, 30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 5 CERES WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES 2 40 S POS TARG 30, 30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 6 CERES WFPC2 IMAGE WF3-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG -10, -10 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 7 CERES WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES 2 40 S SAME POS AS 6 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 1 WFPC2 IMAGE PC1 F606W none none none none 1 N/A CERES 2 WFPC2 IMAGE PC1 F606W none none 1 none 1 N/A CERES 2 WFPC2 IMAGE PC1 F606W none none 2 none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 1 none none none 1 N/A CERES 3 WFPC2 IMAGE WF3-FIX F606W 2 none none none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 4 WFPC2 IMAGE WF3-FIX F606W 1 none 1 none 1 N/A CERES 4 WFPC2 IMAGE WF3-FIX F606W 1 none 2 none 1 N/A CERES 4 WFPC2 IMAGE WF3-FIX F606W 2 none 1 none 1 N/A CERES 4 WFPC2 IMAGE WF3-FIX F606W 2 none 2 none 1 N/A CERES 5 WFPC2 IMAGE WF3-FIX F606W 1 none 1 none 1 N/A CERES 5 WFPC2 IMAGE WF3-FIX F606W 1 none 2 none 1 N/A CERES 5 WFPC2 IMAGE WF3-FIX F606W 2 none 1 none 1 N/A CERES 5 WFPC2 IMAGE WF3-FIX F606W 2 none 2 none 1 N/A CERES 6 WFPC2 IMAGE WF3-FIX F606W none none none none 1 N/A CERES 7 WFPC2 IMAGE WF3-FIX F606W none none 1 none 1 N/A CERES 7 WFPC2 IMAGE WF3-FIX F606W none none 2 none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 9] Visit: 04 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CERES WFPC2 IMAGE WF2-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG -10, 10; GS ACQ SCENARIO BASE1T3; SEQ 1-7 NON-INT; SAME GUIDE STARS 1-7 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 2 CERES WFPC2 IMAGE WF2-FIX F606W CLOCKS=YES 2 40 S SAME POS AS 1 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 CERES WFPC2 IMAGE WF2-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG 30, -30; PATTERN 4 3-5 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 4 CERES WFPC2 IMAGE WF2-FIX F606W CLOCKS=YES 2 20 S POS TARG 30, -30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 5 CERES WFPC2 IMAGE WF2-FIX F606W CLOCKS=YES 2 40 S POS TARG 30, -30 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 6 CERES WFPC2 IMAGE WF4-FIX F606W ATD-GAIN=15 1 0.12 S POS TARG 10, -10 Comments: Short exposure with gain=15 to avoid saturation ------------------------------------------------------------------------------------------------------------------------------------ 7 CERES WFPC2 IMAGE WF4-FIX F606W CLOCKS=YES 2 40 S SAME POS AS 6 Comments: Long saturated exposure to detect faint satellites ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 1 WFPC2 IMAGE WF2-FIX F606W none none none none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W none none 1 none 1 N/A CERES 2 WFPC2 IMAGE WF2-FIX F606W none none 2 none 1 N/A CERES 3 WFPC2 IMAGE WF2-FIX F606W 1 none none none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CERES 3 WFPC2 IMAGE WF2-FIX F606W 2 none none none 1 N/A CERES 4 WFPC2 IMAGE WF2-FIX F606W 1 none 1 none 1 N/A CERES 4 WFPC2 IMAGE WF2-FIX F606W 1 none 2 none 1 N/A CERES 4 WFPC2 IMAGE WF2-FIX F606W 2 none 1 none 1 N/A CERES 4 WFPC2 IMAGE WF2-FIX F606W 2 none 2 none 1 N/A CERES 5 WFPC2 IMAGE WF2-FIX F606W 1 none 1 none 1 N/A CERES 5 WFPC2 IMAGE WF2-FIX F606W 1 none 2 none 1 N/A CERES 5 WFPC2 IMAGE WF2-FIX F606W 2 none 1 none 1 N/A CERES 5 WFPC2 IMAGE WF2-FIX F606W 2 none 2 none 1 N/A CERES 6 WFPC2 IMAGE WF4-FIX F606W none none none none 1 N/A CERES 7 WFPC2 IMAGE WF4-FIX F606W none none 1 none 1 N/A CERES 7 WFPC2 IMAGE WF4-FIX F606W none none 2 none 1 N/A 11969( 7) - 06-Jan-2009 17:59:29 - [ 11] Summary Form for Proposal 11969 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1, PC1-FIX, WF2-FIX, WF3-FIX, WF4-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15, CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 02 BY .9 D TO 1.1 D, GS ACQ SCENARIO BASE1T3, PATTERN 3 1-3, PATTERN 3 3-5, PATTERN 4 1-3, PATTERN 4 3-5, POS TARG -10, -10, POS TARG -10, 10, POS TARG 10, -10, POS TARG 12, 12, POS TARG 30, -30, POS TARG 30, 30, SAME GUIDE STARS 1-7, SAME POS AS 1, SAME POS AS 6, SEQ 01, 02 WITHIN 2.2 Orbits, SEQ 03, 04 WITHIN 2.2 Orbits, SEQ 1-4 NON-INT, SEQ 1-7 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CERES ------------------------------------------------------------------------------------------------------------------------------------