Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5238 Report Date: 18-Jul-95:17:05 Version: ********** Check-in Date: ********** 1.Proposal Title: ASTEROIDS (WC16): CYCLE 4 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GTO/WFC Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. James A. Westphal CALTECH USA (818) 395-4900 PROF, PLANETARY SCI ------------------------------------------------------------------------------------ 7. Abstract There have been a number of visual and photo-electric observations of secondary events associated with occulations of stars by minor planets. These observations are suggestive of satellites for those minor planets. If one minor planet satellite is found, then it is expected that many minor planets would have satellites, unless there is a feature in the process of formation and evolution of the minor planets which favors uniqueness. There are optical, radar and light curve observations indicative of binary asteroids. The negative reports have primarily been for larger asteroids, so it appears that searches should concentrate on average type asteroids. In addition to the significance of satellites of minor planets to the theory of the formation of the solar system, the discovery of satellites and the determination of their periods will permit the determination of the masses of the minor planets. This is the only way to determine accurate values for the masses and hence the densities and compositions. These observations will be used to search for direct images of satellites brighter than 22nd magnitude around several asteroids where unconfirmed observations of satellites have been reported. ------------------------------------------------------------------------------------ 8. Scientific Key Words: ASTEROIDS, SATELLITES ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.65 par: 0 10. Num targs pri: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5238 PI: Prof. James A. Westphal Proposal Title: ASTEROIDS (WC16): CYCLE 4 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ James A. Westphal CALTECH USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. The observation of each asteroid should be made near the time when it is at opposition. The ST should track with the asteroid, so it and any possible satellites would be point images and the stars would be trailed. Three successive exposures should be taken of each asteroid. ------------------------------------------------------------------------------------ 13. Since observations of occultations of stars by asteroids have suggested the existence of satellites of asteroids, a selected list of asteroids will be observed to search for direct images of satellites. ------------------------------------------------------------------------------------ 11. Address Information Name: JAMES A. WESTPHAL Category: PI Institution: CALTECH Address: M/S 170-25 DIVISION OF GEOLOGICAL & PLANETARY SCIENCES City: PASADENA State: CA Zip Code: 91125 Country: USA Telephone: 818-395-4900 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: P. K. SEIDELMANN Category: CON Institution: US NAVAL OBSERVATORY Address: ORBITAL MECHANICS DEPARTMENT City: WASHINGTON State: DC Zip Code: 20392 Country: USA Telephone: (202) 653-1545 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: ED DANIELSON Category: CON Institution: CALTECH Address: M/S 170-25 DIVISION OF GEOLOGICAL & PLANETARY SCIENCES City: PASADENA State: CA Zip Code: 91125 Country: USA Telephone: 818-395-4900 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: SANDRA M. FABER Category: CON Institution: UC SANTA CRUZ - LICK OBSERVATORY Address: NATURAL SCIENCE II City: SANTA CRUZ State: CA Zip Code: 95064 Country: USA Telephone: 408-459-2944 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5238 [ 3] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: 18-MELPOMENE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 18 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=18(MELPOMENE) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: 532-HERCULINA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 532 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=532(HERCULINA) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: 49-PALAS ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 49 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=49(PALAS) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5238 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: 9-METIS ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 9 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=9(METIS) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 | TARGET NAME: 171-OPHELIA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 171 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=171(OPHELIA) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 6 | TARGET NAME: 216-KLEOPATRA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 216 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=216(KLEOPATRA) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5238 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 7 | TARGET NAME: 146-LUCINA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID 146 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=146(LUCINA) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5238 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE # WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 3 3.5S # AST2 CLOCKS=YES Comments: CYCLE 4-5 VERSION; 6/4/93 KAS/ RML ------------------------------------------------------------------------------------------------------------------------------------ 4 USE 18- X1 1 CYCLE 4 / 4-5 AST2 MELPOMENE AT 24-APR-1994 +/- 30D Comments: WITHIN 20D OF OPPOSITION; ------------------------------------------------------------------------------------------------------------------------------------ 5 USE 532- X1 1 AT 13-NOV-1994 +/- AST2 HERCULINA 30D Comments: WITHIN 20D OF OPPOSITION ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5238 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/WFC ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.65 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 4-5; AT 24-APR-1994 +/- 30D; AT 13-NOV-1994 +/- 30D; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 18-MELPOMENE 532-HERCULINA 49-PALAS 9-METIS 171-OPHELIA 216-KLEOPATRA 146-LUCINA ------------------------------------------------------------------------------------------------------------------------------------