6613( 12) - 03/05/96 11:15 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6613 Version: 12 Check-in Date: 05-Mar-1996 11:11:52 1.Proposal Title: The Origin of C_2 in Comets ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle SOLAR SYSTEM GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Michael F. A'Hearn University of Maryland CoI: Claude Arpigny Institut d'Astrophysique N CoI: Paul D. Feldman The Johns Hopkins University N CoI: William M. Jackson University of California - Davis N CoI: Harold A. Weaver Applied Research Corp. N ------------------------------------------------------------------------------------ 6. Abstract We propose to observe any comet satisfying the constraint Q( C_2) > 1.4 * 10^26 s^-1 at r_H = 1 AU to map the Mulliken and Swan bands of C_2. The relative intensities of the singlets and triplets and the excitation temperatures will be mapped as a function of distance from the nucleus. This will constrain the presently unknown formation mechanism for producing C_2 and thus the identity of its parent. It will also constrain the rate for intercombination (singlet-triplet) transitions and thus provide crucial information required for the detailed study of the resonance fluorescence of C_2. ------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 2] Observations Description ------------------------ We propose to use FOS with the G270H grating for the Mulliken bands and with the G570H grating for the Swan bands (only the Delta v = +2 sequence is not covered by this grating). The aperture will be the 1.0 aperture (circular, diameter = 0.86 arcsec) The offsets are nominally at 0, 400, 800, 1600, and 3200 km sunward. On April 2.0, the geocentric distance is such that these offsets correspond to 0, 2, 4, 8, and 16 arcsec. A 25% change in the offsets in km is acceptable as long as the actual offsets are known. In order to not be subject to large errors due to variability of the comet, the G270H and G570H observations will be interleaved in pairs at each offset, one orbit each for the first three positions and 2 orbits each for the last two positions (the two largest offsets). The various spatial positions will all be observed in a single visit. Sufficient signal-to-noise ratio will be achieved with G570H in several seconds so we have adopted a nominal exposure time of 1 minute for all G570H exposures with all remaining time to be devoted to the G270H exposures. The ephemeris of the comet is very uncertain at this time. Even at the time of observation the ephemeris of the comet will not be sufficient for putting the comet in the aperture of FOS. An image with WFPC and real-time analaysis with uplink of an offset will almost certainly be needed to load an offset from the ephemeris. We assume that this program will be executed at essentially the same time as the program of J. Brandt or that of H. Weaver, both of whom wish to observe at nearly the same time and both of whom have WFPC2 images as part of their programs. Images from their programs can be used for the Real-Time Analysis, with only the need for an uplinked offset in our program. In addition to the problem of updating the ephemeris, there is the problem of placing the target precisely in the 1.0 arcsec aperture of FOS. With the spatial scale available for this comet, a guide star uncertainty of 0.8 arcsec is undesirable but tolerable, provided that we know precisely where the target is relative to the FOS aperture, at least for the positions on and nearest the nucleus (for the larger offsets, the 0.8 arcsec uncertainty is not important). We have therefore also requested an FOS IMAGE to map the aperture at the start of each of the first two orbits in order to determine the initial position accurately. We would prefer an ACQ image but there is some chance taht use of the mirror instead of a grating would overload the sensor and trigger a safing. Each orbit in the sequence is treated as a separate visit in order to allow us to use different ephemeris corrections for each orbit and to force a guide star acquisition at the start of each orbit. Nevertheless, we wish the entire sequence to be carried out in successive orbits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 01 | TARGET NAME: C-HYAKUTAKE-OFF0 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET Hyakutake ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.23015585,E=0.99997350,I=1 | 24.886015,O=188.060838,W=130.184765,T = | 01-May- | 1996:09:51:47.0,EQUINOX=J2000,EPOCH=03- | May-1996 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | RANGE EARTH C-HYAKUTAKE-OFF0 LT 0.3 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2 | B-V = 0.7 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 02 | TARGET NAME: C-HYAKUTAKE-OFF2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET COMET Hyakutake ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.23015585,E=0.99997350,I=1 | TYPE=POS_ANGLE,RAD=2.0,ANG=0.0,REF=SUN 24.886015,O=188.060838,W=130.184765,T = | 01-May- | 1996:09:51:47.0,EQUINOX=J2000,EPOCH=03- | May-1996 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | RANGE EARTH C-HYAKUTAKE-OFF2 LT 0.3 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2 | B-V = 0.7 | | ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 5] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 03 | TARGET NAME: C-HYAKUTAKE-OFF4 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET COMET Hyakutake ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.23015585,E=0.99997350,I=1 | TYPE=POS_ANGLE,RAD=4.0,ANG=0.0,REF=SUN 24.886015,O=188.060838,W=130.184765,T = | 01-May- | 1996:09:51:47.0,EQUINOX=J2000,EPOCH=03- | May-1996 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | RANGE EARTH C-HYAKUTAKE-OFF4 LT 0.3 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2 | B-V = 0.7 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 04 | TARGET NAME: C-HYAKUTAKE-OFF8 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET COMET Hyakutake ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.23015585,E=0.99997350,I=1 | TYPE=POS_ANGLE,RAD=8.0,ANG=0.0,REF=SUN 24.886015,O=188.060838,W=130.184765,T = | 01-May- | 1996:09:51:47.0,EQUINOX=J2000,EPOCH=03- | May-1996 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | RANGE EARTH C-HYAKUTAKE-OFF8 LT 0.3 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2 | B-V = 0.7 | | ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 6] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 05 | TARGET NAME: C-HYAKUTAKE-OFF16 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET COMET Hyakutake ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.23015585,E=0.99997350,I=1 | TYPE=POS_ANGLE,RAD=16.0,ANG=0.0,REF=SUN 24.886015,O=188.060838,W=130.184765,T = | 01-May- | 1996:09:51:47.0,EQUINOX=J2000,EPOCH=03- | May-1996 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | RANGE EARTH C-HYAKUTAKE-OFF16 LT 0.3 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2 | B-V = 0.7 | | ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 7] Visit: 10 Visit Requirements: SEQ 10-70 WITHIN 960M BETWEEN 01-APR-96 AND 03-APR-96 GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: I assume that one of the other ToO programs will take an image shortly prior to the start of this program and that this image will be used to generate an ephemeris correction to be uplinked for this program. Use of G570H followed by G270H is chosen for pointing reasons but if time to rotate grating wheel the long-way round is truly excessive, opposite order can be considered. This visit should be completed in one orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 C-HYAKUTAKE FOS/RD IMAGE 4.3 G570H Y-SIZE=5,Y- 1 20S REQ EPHEM CORR HYAKU1 SEQ 10-12 NON-INT -OFF0 SPACE=128,COMB= YES,SUB-STEP=4 Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV ------------------------------------------------------------------------------------------------------------------------------------ 11 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 -OFF0 ------------------------------------------------------------------------------------------------------------------------------------ 12 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 20M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF0 END ORBIT MIN DUR 18M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 8] Visit: 20 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 20 C-HYAKUTAKE FOS/RD IMAGE 4.3 G570H Y-SIZE=5,Y- 1 20S REQ EPHEM CORR HYAKU1 SEQuence 20-22 NON- -OFF2 SPACE=128,COMB= INTerruptible YES,SUB-STEP=4 Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV ------------------------------------------------------------------------------------------------------------------------------------ 21 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 -OFF2 ------------------------------------------------------------------------------------------------------------------------------------ 22 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 20M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF2 END ORBIT MIN DUR 18M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 9] Visit: 30 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 SEQ 31 -OFF4 -32 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 32 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 24M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF4 END ORBIT MIN DUR 20M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 10] Visit: 40 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 SEQ 41 -OFF8 -42 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 42 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 24M REQuires EPHEMeris CORRection HYAKU1 END -OFF8 ORBIT MIN DUR 20M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 11] Visit: 50 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 51 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 SEQ 51 -OFF8 -52 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 52 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 24M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF8 END ORBIT MIN DUR 20M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 12] Visit: 60 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 61 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 SEQ 61 -OFF16 -62 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 62 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 24M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF16 END ORBIT MIN DUR 20M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 13] Visit: 70 Visit Requirements: GUIDing TOLerance 2" SCHED 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 71 C-HYAKUTAKE FOS/RD ACCUM 1.0 G570H 1 60S REQuires EPHEMeris CORRection HYAKU1 SEQ 71 -OFF16 -72 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 72 C-HYAKUTAKE FOS/RD ACCUM 1.0 G270H 1 24M REQuires EPHEMeris CORRection HYAKU1 EXPAND -OFF16 END ORBIT MIN DUR 20M ------------------------------------------------------------------------------------------------------------------------------------ 6613( 12) - 03/05/96 11:15 - [ 14] Summary Form for Proposal 6613 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters Y-SIZE=5 Y-SPACE=128 COMB=YES SUB-STEP=4 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 10-70 WITHIN 960M BETWEEN 01-APR-96 AND 03-APR-96 GUIDing TOLerance 2" SCHED 100% REQ EPHEM CORR HYAKU1 SEQ 10-12 NON-INT REQuires EPHEMeris CORRection HYAKU1 REQuires EPHEMeris CORRection HYAKU1 EXPAND END ORBIT MIN DUR 18M REQ EPHEM CORR HYAKU1 SEQuence 20-22 NON-INTerruptible REQuires EPHEMeris CORRection HYAKU1 SEQ 31-32 NON-INT REQuires EPHEMeris CORRection HYAKU1 EXPAND END ORBIT MIN DUR 20M REQuires EPHEMeris CORRection HYAKU1 SEQ 41-42 NON-INT REQuires EPHEMeris CORRection HYAKU1 END ORBIT MIN DUR 20M REQuires EPHEMeris CORRection HYAKU1 SEQ 51-52 NON-INT REQuires EPHEMeris CORRection HYAKU1 SEQ 61-62 NON-INT REQuires EPHEMeris CORRection HYAKU1 SEQ 71-72 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G570H G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names C-HYAKUTAKE-OFF0 C-HYAKUTAKE-OFF2 C-HYAKUTAKE-OFF4 C-HYAKUTAKE-OFF8 C-HYAKUTAKE-OFF16 ------------------------------------------------------------------------------------------------------------------------------------