! Proposal 6736, submission 3 ! PI: Michael Combi ! Received Fri Feb 23 13:29:33 EST 1996 ! From: mcombi@engin.umich.edu ! Proposal 6736, submission 2 ! PI: Michael Combi ! Received Wed Feb 14 18:17:31 EST 1996 ! From: mcombi@engin.umich.edu ! +====================+ ! | PED OUTPUT PRODUCT | ! +====================+ ! ! /afs/engin.umich.edu/u/m/c/mcombi/6736.HST/6736.prop ! Generated by PREPROCESSOR, version 6.0e ! Date: Fri Feb 9 13:48:53 EST 1996 Proposal_Information Title: A Comprehensive Study of the H Ly--Alpha Line Profile and Water Photochemistry in a TOO Comet Proposal_Category: GO Scientific_Category: SOLAR SYSTEM Cycle: 6 Investigators PI_Name: Michael Combi PI_Institution: University of Michigan CoI_Name: Michael Brown CoI_Institution: California Institute of Technology Contact: CoI_Name: Paul Feldman CoI_Institution: Johns Hopkins University Contact: CoI_Name: H. Uwe Keller CoI_Institution: Max Planck Institute fur Aeronomie Contact: CoI_Name: Robert Meier CoI_Institution: Naval Research Laboratory Contact: CoI_Name: William Smyth CoI_Institution: Atmospheric & Environmental Research, Inc. Contact: Abstract: We propose to undertake a comprehensive study of water production and photochemistry in comets using coordinated HST and ground-based echelle spectroscopic measurements of a bright comet. The brightness and shape of the H LyAlpha line profile will be measured at various locations in the inner coma using GHRS, which has a factor of 4 better spectral resolution than has ever been obtained for LyAlpha in comets and 2 better than ground-based observations of HAlpha. FOS will be used to measure the OH(0-0) emission brightness and monitor any short-term variations. A LyAlpha image of the whole inner coma will be constructed with WFPC 2 using the F160BW and F130LP filters. The HST LyAlpha and OH(0-0) measurements will be coordinated with a ground-based echelle- spectroscopy campaign of observing the HAlpha line profile and the OI 6300Angstrom emission and monitoring the longer term variability of the comet. It is only through the self- consistent analysis of such a coordinated set of observations that we can hope to gain a better quantitative understanding of the details of the production and photochemistry of water in comets, such as: (1) the ejection velocity distribution of H atoms and (via conservation of momentum) OH radicals, (2) the branching ratio of the two main dissociation branches, (3) the effects of collisional thermalization of H atoms, and (4) any spatial and line profile asymmetries from aspherical outgassing. Questions Observing_Description: The observations of the TOO comet will be scheduled at a time of reasonably large geocentric velocity, to minimize interference by any signal from geocoronal hydrogen seen by HST from low earth orbit which should be small compared with the comet in any case. The time of the session would correspond to as optimal an observation as possible given the intrinsic brightness of the comet and the observational geometry constraints. For planning purposes we have adopted the following scenario: a comet with heliocentric and geocentric distances of 1 AU and a water production rate of 2 x 10^29s^-1. The following observations would be made. 1-WFPC 2 image with F675W for targeting the comet 3-FOS spectra of the OH(0-0) band near beginning, middle and end of session 6- GHRS spectra of LyAlpha with ECH-A, side 1 2-WFPC 2 images with F160BW (CR-SPLIT on one orbit) 1-WFPC 2 image with a combination of F160BW and F130LP The comet will be targeted using a WFPC2 image using filter F675W for the purpose of recalibrating the pre-observation ephemeris. The acquisition time has improved to 7.5 minutes, so even for a fast moving comet that needs to be reacquired on each orbit not much time is lost. On the next orbit one FOS spectrum will be taken to obtain a baseline water production rate from the OH (0--0) band emission at 3090Angstrom. Two more will be taken, roughly in the middle and at the end of each session to monitor the short term production rate variation. Our hydrogen coma model has been used to generate an estimated LyAlpha intensity map (see Fig 2). Assuming that an average FWHM of 0.1Angstrom for the intrinsic cometary LyAlpha line, based on the past LyAlpha and HAlpha measurements, and the sensitivity at LyAlpha listed in the GHRS handbook, we have estimated reasonable values for the integration time for each observation and the corresponding count rate and mean signal- to-noise ratio. The background from the combined sources of dark current, radiation noise and random count statistics were also estimated from the information provided in the GHRS handbook. A series of GHRS spectra would begin on the third orbit, consisting of a nucleus-centered spectrum and various offset spectra shown in Table 1. , Table 1 GHRS Comet Observations begintabbing hspace0.1in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=Position(km) .2in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=Brightness(kR) .2in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=Integration Time(s)hspace0.2in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=Counts/Diode .2in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=Orbits .2in\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\=S/N , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>1. Nucleus>>80\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>2000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>>300\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>1\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>>14 , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>2. 5x10^3a>65\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>3000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>320\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>1\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>14 , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>3. 5x10^3b>65\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>3000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>320\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>1\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>14 , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>4. 5x10^3c>65\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>3000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>320\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>1\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>14 , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>5. 3x10^4>35\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>6000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>336\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>2\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>15 , \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>6. 10^5>20\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>12000\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>390\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\! \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>5\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\>13 , endtabbing The three spectra taken at 5x10^3 km (a to c) correspond to 3 directions with respect to the nucleus: sunward, antisunward, and a perpendicular directions (see also Fig. 2). These observations are designed to test for coma asymmetry, which could be due to non-spherical outgassing, optical depth effects or both. In the most general case one could expect both the integrated line intensity as well as the line shape to vary around an optically thick coma, even if the gas is spherically symmetric. In the case of aspherical gas ejection, the line itself could display a Doppler shifted offset. For a comet at 1 AU from the sun the spectrum at an offset of 10^5 km should contain equal contributions of H produced directly from water and that produced by OH. The coma at that distance should also be much less optically thick. After this, two WFPC 2 images in WF 3 with aperture F160BN15 (i.e., rotated 15 degrees), will be taken. With these a LyAlpha image can be constructed (Clarke et al. 1995). First an image (actually 2 images assuming CR-SPLIT) will be recorded using the F160BW (Woods) filter. This yields an image of the entire far UV spectrum of the comet ( dominated by LyAlpha. Next an image using the combination of F160BW with F130LP will be taken. This yields an image with a slightly reduced throughput of the far UV less the LyAlpha ( light and light leak. This can all be accomplished on one orbit. All observations can be acquired in 15 orbits: 11 for the GHRS spectra, 1 for the targeting WFPC 2 (G675W)image, 1 for the three far UV WFPC 2 images (2-F160BW and 1-F160BW+F130LP) and 2 for the OH FOS spectrum. All estimates for numbers of orbits account for a realistic 35 minutes per orbit for target reacquisition and integration on a moving target at the declination of the comet, given the theoretical upper limit of 53 minutes per orbit for all maneuvers. sectionReferences Brown and Spinrad (1993) Icarus, 104, 197 Budzien, Festou and Feldman (1994) Icarus, 107, 164 Carruthers et al. (1974) Icarus, 23, 526 Clarke et al. (1995) ``Far UV Imaging with the HST WFPC2'' (preprint) Cochran and Schleicher (1993) Icarus, 105, 235 Code, Houcke and Lillie (1972) NASA SP-310, pp. 109-114 Combi (1989) Icarus, 81, 41 Combi and Feldman (1992) Icarus, 97, 260 Combi and Feldman (1993) Icarus, 105, 557 Combi and Smyth (1988a&b) ApJ, 327, 1026 & ApJ, 327, 1044 Crovisier (1989) A&A, 213, 459 Feldman et al. (1974) Science, 185, 705 Festou et al. (1979) ApJ, 232, 318 Huppler et al. (1975) ApJ, 202, 276 Keller and Meier (1976) A&A, 52, 272 Meier et al. (1976) A&A, 52, 283 Schleicher and A'Hearn (1982 & 1988) ApJ, 258, 864, & ApJ, 331, 1058 Smyth et al. (1993) ApJ, 413, 756 Smyth et al. (1995) ApJ, 440, 349 van Dishoeck and Dalgarno (1984) Icarus, 59, 305 Wu and Chen (1993) JGR-Planets, 98, 7415 Real_Time_Justification: In order to coordinate with the ground-based observations it would be most desirable to have some forewarning as to the scheduling of the comet observation. As a target-of- opportunity object scheduling would occur after identification of a suitable comet. The probability of occurrence of a moderate comet could be about once in 2 or 3 years. Since GHRS will only be available for about the half of Cycle 6 before the shuttle service mission the probability is about 1/6 to 1/4. The recently discovered comet Hale-Bopp has the potential to be a fairly bright comet, but its proximity to the sun in the sky will probably make HST observations difficult when (or if) the comet is bright. Along with the HST measurements, we will obtain simultaneous ground-based measurements of the HAlpha line with the Hamilton echelle spectrograph on the coude auxiliary telescope (CAT) at Lick Observatory. The CAT is undersubscribed, so we expect to be able to mount an intensive observing campaign on short notice. The ability to simultaneously match observations at LyAlpha and HAlpha will provide a vital constraint on the hydrogen coma model and optical depth calculations. In addition, the relative advantages and disadvantages of the HST and ground-based measurements precisely complement one another. One primary difficulty in the HST measurement is the optical depth at the LyAlpha line center. A comet, however, is a factor of about 5 less optically thick to solar LyBeta which excites the HAlpha emission than to solar LyAlpha. With the long-slit HAlpha spectrum we will then be able to precisely connect LyAlpha measurements taken at locations in the coma with high optical depth with those at low optical depth. On the other hand, the HAlpha measurement suffers from the difficulty of the subtraction of the strong dust continuum and from the large numbers of unidentified spectral lines in the vicinity (see Fig 1). These difficulties make it particularly hard to use the HAlpha observations to measure the velocities in the faint wings of the line (Brown & Spinrad 1993). The HST measurement will have neither of these problems -- and LyAlpha is optically thin in the line wings -- so it will provide the first reliable direct measurement of the high- velocity hydrogen. Calibration_Justification: Additional_Comments: Fixed_Targets Solar_System_Targets Target_Number: 1 Target_Name: B2 Description: COMET B2-NUCLEUS Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: Level_3: Window: RVEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Target_Number: 2 Target_Name: B2-OFFSET-2 Description: COMET B2-OFFSET-2 Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: TYPE=POS_ANGLE,RAD=23.0,ANG=0.0,REF=SUN Level_3: Window: R_VEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Target_Number: 3 Target_Name: B2-OFFSET-3 Description: COMET B2-OFFSET-3 Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: TYPE=POS_ANGLE,RAD=23.0,ANG=180.0,REF=SUN Level_3: Window: R_VEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Target_Number: 4 Target_Name: B2-OFFSET-4 Description: COMET B2-OFFSET-4 Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: TYPE=POS_ANGLE,RAD=23.0,ANG=90.0,REF=SUN Level_3: Window: R_VEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Target_Number: 5 Target_Name: B2-OFFSET-5 Description: COMET B2-OFFSET-5 Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: TYPE=POS_ANGLE,RAD=138.0,ANG=0.0,REF=SUN Level_3: Window: R_VEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Target_Number: 6 Target_Name: B2-OFFSET-6 Description: COMET B2-OFFSET-6 Level_1: TYPE=COMET,Q=0.2294915,E=1.0000000,I=124.65024,O=188.15597,W=130.29556,T=01-May-1996:13:16:14.0,EQUINOX=J2000,EPOCH=07-Feb-1996 Level_2: TYPE=POS_ANGLE,RAD=461,ANG=0.0,REF=SUN Level_3: Window: R_VEL B2 EARTH GT 40 RANGE B2 EARTH LT 0.6 RANGE B2 SUN LT 1.2 Ephem_Uncert: 10000 KM Acq_Uncert: 20 " Flux: V = 10 B-V = 0.8 V-R = 0.4 Comments: Requires ephemeris correction. Generic_Targets Scan_Data Visits Visit_Number: 01 Visit_Requirements: GUID TOL 0.2" GROUP 1-15 WITHIN 36H BETWEEN 29-MAR-96 AND 4-APR-96 SCHED 100% On_Hold_Comments: Visit_Comments: Visit should be completed in one orbit. Uplink offset correction to comet ephemeris before next Visit. RANGE and BETWEEN requirements define same window. Exposure_Number: 11 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 5S Special_Requirements: SAVE OFFSET B2 REQ EPHEM CORR B2A Comments: Determines ephemeris corrections for all other visits. Exposure_Number: 12 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 10S Special_Requirements: REQ EPHEM CORR B2A Comments: Determines ephemeris corrections for all other visits. Exposure_Number: 13 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 20S Special_Requirements: REQ EPHEM CORR B2A Comments: Determines ephemeris corrections for all other visits. Exposure_Number: 14 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: F160BN15 Sp_Element: F160BN15 Wavelength: Optional_Parameters: CR-SPLIT=DEF,ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 20M Special_Requirements: REQ EPHEM CORR B2A Visit_Number: 02 Visit_Requirements: GUID TOL 0.2" GROUP 2-7 WITHIN 11H after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Before Visit 02 enough time is needed to uplink comet offset corrections based on images from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 21 Target_Name: B2 Config: FOS/RD Opmode: IMAGE Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Y-SIZE=5 Y-SPACE=128 COMB=YES SUB-STEP=4 Number_of_Iterations: 1 Time_Per_Exposure: 300S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV Exposure_Number: 22 Target_Name: B2 Config: FOS/RD Opmode: ACCUM Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 19M Special_Requirements: EXPAND END ORBIT USE OFFSET B2 REQ EPHEM CORR B2A MIN DUR 18M Comments: Visit_Number: 03 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 30 Target_Name: B2 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 1 Time_Per_Exposure: 652.8S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Nucleus-centered spectrum. Exposure_Number: 31 Target_Name: B2 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 1 Time_Per_Exposure: 652.8S Special_Requirements: SEQ 31-32 NON-INT USE OFFSET B2 REQ EPHEM CORR B2A Comments: Nucleus-centered spectrum. Exposure_Number: 32 Target_Name: WAVE Config: HRS Opmode: ACCUM Aperture: SC2 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: SPYBAL=NO Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: SAME POS AS 31 USE OFFSET B2 REQ EPHEM CORR B2A Comments: Wavelength Calibration Visit_Number: 04 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 41 Target_Name: B2-OFFSET-2 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 5000 km sunward. Visit_Number: 05 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 51 Target_Name: B2-OFFSET-3 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 5000 km antisunward. Visit_Number: 06 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 61 Target_Name: B2-OFFSET-4 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 5000 km normal to sun-comet line. Visit_Number: 07 Visit_Requirements: GUID TOL 1.0" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 71 Target_Name: B2-OFFSET-5 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 30000 km sunward. Visit_Number: 08 Visit_Requirements: GUID TOL 1.0" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 81 Target_Name: B2-OFFSET-5 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 30000 km sunward. Visit_Number: 09 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 91 Target_Name: B2 Config: FOS/RD Opmode: IMAGE Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Y-SIZE=5 Y-SPACE=128 COMB=YES SUB-STEP=4 Number_of_Iterations: 1 Time_Per_Exposure: 300S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV Exposure_Number: 92 Target_Name: B2 Config: FOS/RD Opmode: ACCUM Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 19M Special_Requirements: EXPAND END ORBIT USE OFFSET B2 REQ EPHEM CORR B2A MIN DUR 18M Comments: Visit_Number: 10 Visit_Requirements: GUID TOL 2.0" GROUP 10-15 WITHIN 11H after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 100 Target_Name: B2-OFFSET-6 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 1 Time_Per_Exposure: 652.8S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 100000 km sunward. Exposure_Number: 101 Target_Name: B2-OFFSET-6 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 1 Time_Per_Exposure: 652.8S Special_Requirements: SEQ 101-102 NON-INT USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 100000 km sunward. Exposure_Number: 102 Target_Name: WAVE Config: HRS Opmode: ACCUM Aperture: SC2 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: SPYBAL=NO Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: SAME POS AS 101 USE OFFSET B2 REQ EPHEM CORR B2A Comments: Wavelength Calibration Visit_Number: 11 Visit_Requirements: GUID TOL 2.0" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 111 Target_Name: B2-OFFSET-6 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 100000 km sunward. Visit_Number: 12 Visit_Requirements: GUID TOL 2.0" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 121 Target_Name: B2-OFFSET-6 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 100000 km sunward. Visit_Number: 13 Visit_Requirements: GUID TOL 2.0" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 131 Target_Name: B2-OFFSET-6 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1215 Optional_Parameters: FP-SPLIT=TWO Number_of_Iterations: 3 Time_Per_Exposure: 489.6S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Offset 100000 km sunward. Visit_Number: 14 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 141 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: F160BN15 Sp_Element: F130LP,F160BN15 Wavelength: Optional_Parameters: CR-SPLIT=NO,ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 7M Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Exposure_Number: 142 Target_Name: B2 Config: WFPC2 Opmode: IMAGE Aperture: F160BN15 Sp_Element: F160BN15 Wavelength: Optional_Parameters: CR-SPLIT=DEF,ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 15M Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Visit_Number: 15 Visit_Requirements: GUID TOL 0.2" after 1 by 5h to 36h SCHED 100% On_Hold_Comments: Visit_Comments: Requires ephemeris corrections from Visit 01. Use "use offset" for all exposures this visit. Exposure_Number: 151 Target_Name: B2 Config: FOS/RD Opmode: IMAGE Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Y-SIZE=5 Y-SPACE=128 COMB=YES SUB-STEP=4 Number_of_Iterations: 1 Time_Per_Exposure: 300S Special_Requirements: USE OFFSET B2 REQ EPHEM CORR B2A Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV Exposure_Number: 152 Target_Name: B2 Config: FOS/RD Opmode: ACCUM Aperture: 4.3 Sp_Element: G270H Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 19M Special_Requirements: EXPAND END ORBIT USE OFFSET B2 REQ EPHEM CORR B2A MIN DUR 18M Comments: Data_Distribution ! Defaults indicated; change if desired Medium: 8MM Blocking_Factor: 10 Ship_To: PI_Address Ship_Via: UPS Recipient_Email: ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator