Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2442c Report Date: 09-May-96:17:07 Version: ********** Check-in Date: ********** 1.Proposal Title: COMETARY PARENT MOLECULES ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category COMETS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. Paul D. Feldman JOHNS HOPKINS UNIVERSITY USA 410-516-7339 PROFESSOR OF PHYSICS ------------------------------------------------------------------------------------ 7. Abstract We propose to use HRS observations of a suitable target-of-opportunity comet to study two outstanding problems related to the composition of the volatile component of the cometary nucleus. These problems concern two species, CO and S2, which have been observed in the cometary coma and identified as "parent" molecules sublimating directly from the nucleus. Both of these molecules have their principal fluorescent emissions in the vaccuum ultraviolet. The high spectral resolution will allow the determination of the rotational temperature of CO, which is diagnostic of the source temperature and the excitation mechanism of the observed emission. The determination of the abundance of both CO and S2 in the primarily water ice of the nucleus can serve to constrain current models of comet formation in the primordial solar nebula. ------------------------------------------------------------------------------------ 8. Scientific Key Words: COMETS, SPECTROSCOPY, ULTRAVIOLET ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.90 par: 0 10. Num targs pri: 3 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2442c PI: Prof. Paul D. Feldman Proposal Title: COMETARY PARENT MOLECULES ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Prof. Michael F. A'Hearn MARYLAND, UNIVERSITY OF USA Prof. Paul D. Feldman JOHNS HOPKINS UNIVERSITY USA Dr. Harold A. Weaver STSCI USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. Due to the motion of the comet on the sky, which is typically greater than 2 arc minutes per hour, it will be necessary to use a different pair of guide stars for each visit to the comet. During the first visit, a WFC image will be obtained with real-time contact to verify the calculated ephemeris position and moving target rate. WFC images will be taken after each GHRS exposure to determine the actual pointing during data analysis. All of the science data will be acquired using the Large Science Aperture (LSA) of the GHRS. The following observations will be made: (This section was modified 30 September 1991 because of the problem with side 1 of the GHRS.) 1) Use G160M in three separate bands to observe the major CO Fourth Positive Bands to determine both the optical depth in the strong (2,0) and (1,0) bands and the rotational temperature. The (0,0) band region also includes CI lambda 1561 for comparison with models of CO destruction in the coma. For each of four exposures, the center-of- brightness of the comet is centered in the LSA. The exposure times are 20 and 25 minutes. 2) Repeat (1) in each of the three bands but offset the LSA 10,000 km from the center-of-brightness towards the sun. The exposure times are 30 and 32 minutes. 3) Use G270M at two discrete wavelengths to observe the strongest S2 bands. One of these bands includes the OH(1,0) band to provide a simultaneous measure of the water production rate. The comet is centered in the LSA. 4) Use G270M in one band, offset by 2" parallel to an edge of the LSA, to determine scalelength of S2. 5) Repeat (3) after several orbits to search for time variability. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. This is a target-of-opportunity program to be activated upon the apparition of a suitable comet. The observations are time-critical in that a comet will be optimally placed for observation only for a period of days or weeks. Real-time contact is necessary to establish the correctness of the cometary ephemeris, both for position and moving target rate. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. The probability of occurence of a suitable target-of-opportunity comet can be estimated using our collective experience with IUE since the observing constraints (e.g., solar avoidance angle) are similar to those for HST. During the past ten years, of the 30 comets observed by IUE, 14 were target-of- opportunity and 16 were known periodic comets (P/Encke was observed on 3 separate apparitions; P/Borrelly on 2). Of the 14, 5 of the target-of-opportunity comets satisfied the criteria given in Section 5 above, so that the probability of occurence is 50%. It should also be noted that a long time (12.5 years) has elapsed since the apparition of a bright "naked-eye" comet (West 1976 VI) and although these occur with a frequency of one or two per decade, none has appeared since the launch of IUE. ------------------------------------------------------------------------------------ 11. Address Information Page 3 Name: PAUL D. FELDMAN Category: PI Institution: CENTER FOR ASTROPHYSICAL SCIENCES Address: JOHNS HOPKINS UNIVERSITY DEPT. OF PHYSICS AND ASTRONOMY City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 2442c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: COMET-SL-1991A1 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET SHOEMAKER LEVY 1991A1 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE = COMET, | Q = 0.8367203, E = 0.9998587, | O = 49.05506, W = 145.22740, | I = 113.50885, | T = 24-JUL-92:13:16:48, | EQUINOX = J2000, | EPOCH = 06-AUG-92, ACQ = 0.25 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 12 +/- 1 | OPTIMUM OBSERVING TIME IS NEAR 2 |SURF-LINE(1510) = 15 +/- 5 E-15 | PERIHELION. NOMINAL PERIHELION DATE 3 |W-LINE(1510) = 1.0 +/- 0.2 | IS 24 JUL 1992 BUT WILL NEED 4 |SURF-LINE(2900) = 50 +/- 20 E-15 | UPDATING AFTER THE COMET IS 5 |W-LINE(5730) = 1.0 +/- 0.2 | RECOVERED. TOTAL COMA VISUAL 10 |SIZE = 1 | MAGNITUDE SHOULD BE ABOUT 7 DURING | | THE TIME OF OBSERVATIONS BUT THIS IS | | UNCERTAIN. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 2442c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: COMET-SL-OFFSET ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET COMET SHOEMAKER LEVY 1991A1 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE = COMET, | TYPE = POS_ANGLE, Q = 0.836720, E = 0.9998587, | RAD = 15.3, O = 49.05506, W = 145.2274, | ANG = 0, I = 113.50885, | REF = SUN T = 24-JUL-92:13:16:48, | EQUINOX = J2000, | EPOCH = 06-AUG-92, ACQ = 0.25, | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 12 +/- 1 | OPTIMUM OBSERVING TIME IS NEAR 2 |SURF-LINE(1510) = 15 +/- 5 E-15 | PERIHELION. NOMINAL PERIHELION DATE 3 |W-LINE(1510) = 1.0 +/- 0.2 | IS 24 JUL 1992 BUT WILL NEED 4 |SURF-LINE(2900) = 50 +/- 20 E-15 | UPDATING AFTER THE COMET IS 5 |W-LINE(5730) = 1.0 +/- 0.2 | RECOVERED. TOTAL COMA VISUAL 10 |SIZE = 1 | MAGNITUDE SHOULD BE ABOUT 7 DURING | | THE TIME OF OBSERVATIONS BUT THIS IS | | UNCERTAIN. THIS PTG IS OFFSET ABOUT | | 10000 KM FROM THE NUCLEUS TOWARD THE | | SUN. | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 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 COMET-SL- WFC IMAGE W2 F785LP PRE-FLASH=YES 1 20 S 1 1 POS TARG -20,+20 IMAGE 1991A1 CR-SPLIT=NO 10 Comments: WFC IMAGE IS USED FOR DETERMINING POINTING ERROR. TARGET IS TO BE PLACED AT ABOUT 20 ARCSEC FROM THE PYRAMID APEX. ------------------------------------------------------------------------------------------------------------------------------------ 1.1 DEFINE COMET-SL- WFC IMAGE W2 F785LP PRE-FLASH=NO 1 0.11 S 1 3 POS TARG -20,+20 IMAGE- 1991A1 CR-SPLIT=NO 10 DUM Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1595 FP-SPLIT=STD 1 20M 10 2 1 ON-1595 1991A1 30M Comments: NUCLEUS POINTING. ------------------------------------------------------------------------------------------------------------------------------------ 2.1 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1595 FP-SPLIT=STD 1 57.6S 10 2 3 DUMMY- 1991A1 30M 1595 Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 3 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1595 FP-SPLIT=STD 1 20M 5 2 4 OFF- OFFSET 40M 1595 Comments: OFFSET 10000 KM SUNWARD FROM THE NUCLEUS. ------------------------------------------------------------------------------------------------------------------------------------ 4 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1475 FP-SPLIT=STD 1 20M 10 2 1 ON-1475 1991A1 30M Comments: NUCLEUS POINTING. ------------------------------------------------------------------------------------------------------------------------------------ 4.1 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1475 FP-SPLIT=STD 1 57.6S 10 2 3 DUMMY- 1991A1 30M 1475 Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 5 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1475 FP-SPLIT=STD 1 20M 5 2 3 OFF- OFFSET 40M 1475 Comments: OFFSET 10000 KM SUNWARD FROM THE NUCLEUS. ------------------------------------------------------------------------------------------------------------------------------------ 6 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1550 FP-SPLIT=STD 1 20M 10 2 1 ON-1550 1991A1 30M Comments: NUCLEUS POINTING. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 6.1 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1550 FP-SPLIT=STD 1 57.6S 10 2 3 DUMMY- 1991A1 30M 1550 Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 7 DEFINE COMET-SL- HRS ACCUM 2.0 G160M 1550 FP-SPLIT=STD 1 20M 5 2 4 OFF- OFFSET 40M 1550 Comments: OFFSET 10000 KM SUNWARD FROM THE NUCLEUS. ------------------------------------------------------------------------------------------------------------------------------------ 8 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2905 FP-SPLIT=STD 1 20M 10 4 1 ON-2905 1991A1 30M Comments: NUCLEUS POINTING. ------------------------------------------------------------------------------------------------------------------------------------ 8.1 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2905 FP-SPLIT=STD 1 57.6S 10 4 3 DUMMY- 1991A1 30M 2905 Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 9 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2905 FP-SPLIT=STD 1 20M 5 4 4 OFF- OFFSET 40M 2905 Comments: OFFSET 10000 KM SUNWARD FROM THE NUCLEUS. ------------------------------------------------------------------------------------------------------------------------------------ 10 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2844 FP-SPLIT=STD 1 20M 10 4 1 ON-2844 1991A1 30M Comments: NUCLEUS POINTING. ------------------------------------------------------------------------------------------------------------------------------------ 11.1 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2844 FP-SPLIT=STD 1 57.6S 10 4 3 DUMMY- 1991A1 30M 2844 Comments: DUMMY EXP FOR USE WHEN TRACKING UNDER GYRO CONTROL. EXP TIME IS ARBITRARY. ------------------------------------------------------------------------------------------------------------------------------------ 12 DEFINE COMET-SL- HRS ACCUM 2.0 G270M 2844 FP-SPLIT=STD 1 20M 5 4 4 OFF- OFFSET 40M 2844 Comments: OFFSET 10000 KM SUNWARD FROM THE NUCLEUS. ------------------------------------------------------------------------------------------------------------------------------------ 13 USE IMAGE- DUM Comments: USE ONLY IF NEXT WFC IMAGE REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 13.1 USE RT ANALYSIS FOR IMAGE 14.1,15.1,16.1 DEC TIME 8.5M SEQ 13.1-16.1 WITHIN 1D CRIT OBS / 13.0- 27.1 TARG OF OPP / 13.0 -27.1 CYCLE 1 / 13.0- 27.1 ------------------------------------------------------------------------------------------------------------------------------------ 14 USE DUMMY- 1475 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 14.1 USE ON- 1475 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 15 USE DUMMY- 1550 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 15.1 USE ON- 1550 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 16 USE DUMMY- 1595 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 16.1 USE ON- 1595 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 17 USE IMAGE- DUM Comments: USE ONLY IF NEXT WFC IMAGE REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 9] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 17.1 USE RT ANALYSIS FOR IMAGE 18.1,19.1,20.1 DEC TIME 8.5M SEQ 17.1-20.1 WITHIN 1D ------------------------------------------------------------------------------------------------------------------------------------ 18 USE DUMMY- 1475 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 18.1 USE ON- 1475 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 19 USE DUMMY- 1475 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 19.1 USE OFF -1475 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 20 USE DUMMY- 1595 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 20.1 USE ON- 1595 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 21 USE IMAGE- DUM Comments: USE ONLY IF NEXT WFC IMAGE REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 21.1 USE RT ANALYSIS FOR IMAGE 22.1,23.1,24.1 DEC TIME 8.5M SEQ 21.1-24.1 WITHIN 1D ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 10] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 22 USE DUMMY- 2905 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 22.1 USE ON- 2905 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 23 USE DUMMY- 2844 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 23.1 USE ON- 2844 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 24 USE DUMMY- 1550 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 24.1 USE ON- 1550 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 25 USE IMAGE- DUM Comments: USE ONLY IF NEXT WFC IMAGE REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 25.1 USE RT ANALYSIS FOR IMAGE 26.1,27.1 DEC TIME 8.5M SEQ 25.1-27.1 WITHIN 1D ------------------------------------------------------------------------------------------------------------------------------------ 26 USE DUMMY- 2905 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2442c [ 11] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 26.1 USE ON- 2905 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ 27 USE DUMMY- 2844 Comments: USE ONLY IF THE FOLLOWING GHRS EXP REQUIRES GYRO TRACKING. ------------------------------------------------------------------------------------------------------------------------------------ 27.1 USE ON- 2844 Comments: POINTING OFFSET COMMAND MUST BE UPLINKED PRIOR TO THIS EXP. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2442c [ 12] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PRE-FLASH=YES CR-SPLIT=NO PRE-FLASH=NO FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.90 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category COMETS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG -20,+20; RT ANALYSIS FOR 14.1,15.1,16.1; DEC TIME 8.5M; SEQ 13.1-16.1 WITHIN 1D; CRIT OBS / 13.0-27.1; TARG OF OPP / 13.0-27.1; CYCLE 1 / 13.0-27.1; RT ANALYSIS FOR 18.1,19.1,20.1; SEQ 17.1-20.1 WITHIN 1D; RT ANALYSIS FOR 22.1,23.1,24.1; SEQ 21.1-24.1 WITHIN 1D; RT ANALYSIS FOR 26.1,27.1; SEQ 25.1-27.1 WITHIN 1D; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F785LP G160M G270M ------------------------------------------------------------------------------------------------------------------------------------ Target Names COMET-SL-1991A1 COMET-SL-OFFSET ------------------------------------------------------------------------------------------------------------------------------------