! Proposal 6447, submission 1 ! PI: Karen J. Meech ! Received Fri Feb 9 20:18:34 EST 1996 ! From: meech@pavo.IFA.Hawaii.Edu ! +====================+ ! | PED OUTPUT PRODUCT | ! +====================+ ! ! /scr9/hstcycle6/6447.prop ! Generated by PREPROCESSOR, version 6.0e ! Date: Thu Feb 8 14:46:17 HST 1996 Proposal_Information Title: Distant Comet Nucleus Sizes Proposal_Category: GO Scientific_Category: SOLAR SYSTEM Cycle: 6 Investigators PI_Name: Karen J. Meech PI_Institution: Institute for Astronomy CoI_Name: Olivier R. Hainaut CoI_Institution: Institute for Astronomy Contact: Abstract: Three well-observed dynamically new comets will be between heliocentric distances, r = 20-28 AU during cycle 6 where it will be possible for the first time to detect their nuclei. These comets are part of a 10 year ground-based program to search for physical and chemical differences between the comets first entering the inner Solar System and those which have been thermally processed. Their gradual comae disappearance has been monitored from the ground, yet nucleus observations have been impossible through the extensive dust comae. The comet nucleus properties are not only essential for using thermal sublimation models to understand the light- curve behavior, but also extremely important to the models of the outer Solar System formation. Cycle 6 will be the last opportunity to obtain physical information on the nuclei in this unique database before they become forever too faint to be observed. The WFPC2 will be used to detect the nuclei to a limiting magnitude of m_R=28. Non-detections are improbable; however, the corresponding constraints (3.4-6.4 km) would be extremely strong, and equally important. Small nucleus sizes, combined with thermal sublimation models, will rule out the hypothesis that distant, unusually active comets must be large, rather that they must have a greater abundance of highly volatile species. The HST observations will be combined with the ground-based observations to make inferences relevant to our understanding of the early solar system. Questions Observing_Description: WFC imaging for comets between r = 20.8-28.0 AU will be done through the F675W filter (R-band) to get the highest S/N possible. Estimates for the nucleus sizes & brightnesses for the targets have been obtained from ground-based non- detection limits, or from detections when coma was present between r = 8-20AU. The m_R shown Table 1 are bright limits. For detections to 28th mag (at S/N=5), very tight physical constraints may be placed on the nucleus sizes, ranging from R_N = 3.4-6.4 km at the beginning of cycle 6 (3.9-7.0 km at the end). Using the WFPC2 Instrument Handbook, we calculate that this will require a total integration between 11,000-15,000 s / comet nucleus (depending on the object's ecliptic latitude, hence background brightness level). These exposure times will allow the detection (S/N=3) of any residual comae to a limit of 24.7 mag arcsec^-2 in m_R. Because of the undersampling of the PSF in the wide field mode, and the need to go very faint, the telescope must be dithered between exposures. As in the case of our upcoming cycle 5 observations for 2 distant comets, we found that exposures of 800, 900, and 1000 sec in CR-split mode would pack optimally into 7 orbits to give a total integration time just over 13,000 sec per comet. This includes the overheads associated with dithering, guide star acquisition, and re-acquisition. We also request the low-sky observation mode to ensure that the zodiacal light brightness is at minimum to enable us to make the faintest detections possible. Although 1 target, Torres, could possibly be observed in a CVZ, this is inconsistent with a low-sky request. The latter is more important because it has a significant affect on the S/N to which we can detect objects near m~28. During the Phase II portion of the observing prepartions, we have plotted the entire track of each comet's orbit for all of cycle 6 to create a list of scheduling windows when the comets (i) have no objects (to the limit of the digital sky survey) within 5 arcsec, (ii) have no object on the orbit within 3 hrs of the comet in its orbit, (iii) have nothing bright (i.e. diffraction spikes visible) in the CCD field, and (iv) have at least 6 hours of observation available, and are (v) at a solar elongation > 100 deg. This will minimize the possibility of field star contamination, and will ensure a lower sky brightness. Because all of the program objects have been well-observed by the PI, we know the orbits to an accuracy of 1-2 arcsec so that this is a feasible observing constraint. The wide field mode is preferred over the PC mode for greater coverage for astrometry, for greater ability to detect the low-surface-brightness comae, and to achieve the faintest limits on point sources. Real_Time_Justification: None. These comets are part of a database of objects which have been observed extensively from the ground during the past 10 years to follow the changes in the comae as a function of heliocentric distance. These observations will place final limits on the nucleus sizes which will constrain the models for the cometary activity. This program has been supported with approximately 10 nights on the CTIO 4m telescope, 20 nights on the CTIO 1.5m, 0.9m and Schmidt telescopes, 20 nights on the ESO NTT, 6 nights on the KPNO 4m and 2.1m telescopes, 3 nights on the Canada-France-Hawaii Telescope, 105 nights on the University of Hawaii 2.2m telescope, and 1 night on the Keck 10m telescope. The Keck observations, made during 1/95 will be used in combination with the cycle 5 observations of the same comets (Shoemaker 1986 XIV and Shoemaker 1985 XII) to constrain the amount of low-surface brightness dust comae which might still be present. The Keck is better suited to the detection of the low surface brightness comae. Related to this program, the co-I has been given 6 nights at ESO 3.6m to study the physical nature of Kuiper Belt objects. \\input epsf epsfxsize15cm\\epsffilet_slide.eps noindent Figure 2a: Composite image of Torres 1987V obtained with the MKO & CTIO telescopes. The distances of the observations range between r = 3.65--13.34 AU. Scale bars show 10^5 km at the comet. begintabularp4.2cmp4.2cmp4.2cm epsfxsize4.2cm\\epsffilet1.eps& epsfxsize4.2cm\\epsffilet2.eps& epsfxsize4.2cm\\epsffilet3.eps, epsfxsize4.2cm\\epsffilet4.eps& epsfxsize4.2cm\\epsffilet5.eps& epsfxsize4.2cm\\epsffilet6.eps, epsfxsize4.2cm\\epsffilet7.eps& epsfxsize4.2cm\\epsffilet8.eps& epsfxsize4.2cm\\epsffilet9.eps, epsfxsize4.2cm\\epsffilet10.eps& epsfxsize4.2cm\\epsffilet11.eps, endtabular noindent Figure 2b: Diagrams of the syndynes and synchrones for comet Torres 1987V which correspond to the images in Figure 2a at r = 3.65, 4.16, 4.45, 4.75, 5.06, 6.31, 7.42, 8.76, 10.94, 11.29, and 13.34 AU. Calibration_Justification: Additional_Comments: The comets selected for this proposal are the highest priority scientifically, however, we had originally included several other targets in the proposal. Should the present objects be impossible to schedule, we have pre-approved alternative objects. See comments under the Visit requirements regarding the sized of the observing windows. Solar_System_Targets Target_Number: 01 Target_Name: COMET-CERNIS-83O1 Description: COMET CERNIS C1983-O1 Level_1: TYPE=COMET , Q = 3.3140197 , E = 1.0001286 , I = 134.70407 , O = 209.61817 , W = 186.20573 , T = 16-JUL-83:11:34:06 , EQUINOX = J2000 , EPOCH = 23-DEC-96 Flux: V = 28.33+/-0.0 V-R = 0.33+/-0.01 Comments: R=28.00 is desired detection limit. Comet might be as bright as R=26. Ephemeris file spike_6447_1.trh was constructed by A. Lubenow from orbital elements provided by PI from B. Marsden. Target_Number: 02 Target_Name: COMET-SHOEMAKER-88B1 Description: COMET SHOEMAKER 1987IV,C1988 B1 Level_1: TYPE=COMET , Q = 5.0355197 , E = 1.0009632 , I = 80.64474 , O = 325.35826 , W = 124.22030 , T = 18-MAR-87:14:33:55.3 , EQUINOX = J2000 , EPOCH = 23-DEC-96 Flux: V = 28.33+/-0.0 V-R = 0.33+/-0.01 Comments: R=28.00 is desired detection limit. Comet might be as bright as R=26. Ephemeris file spike_6447_2.trh was constructed by A. Lubenow from orbital elements provided by PI from B. Marsden. Target_Number: 03 Target_Name: COMET-TORRES-87F1 Description: COMET TORRES 1987V,C1987 F1 Level_1: TYPE=COMET , Q = 3.6480705 , E = 1.0004685 , I = 124.02201 , O = 194.60652 , W = 329.32855 , T = 09-APR-87:09:02:46 , EQUINOX = J2000 , EPOCH = 23-DEC-96 Flux: V = 28.33+/-0.0 V-R = 0.33+/-0.01 Comments: R=28.00 is desired detection limit. Comet might be as bright as R=26. Ephemeris file spike_6447_3.trh was constructed by A. Lubenow from orbital elements provided by PI from B. Marsden. Visits Visit_Number: 01 Visit_Requirements: On_Hold_Comments: Visit_Comments: Windows selected (file spike_6447_1.wnd made by A. Lubenow) so that the field stars do not interfere with observations. The constraints are that there is no object within 5" from the comet's orbit, nor along the orbit for +/- 3 hours, nothing bright in the FOV of the CCD (with diffraction spikes visible), most have at least 6 consecutive hrs of observation, and have a solar elongation greater than 100 deg. The windows should be OR'ed. Note if total scheduling windows are thus too constraining to be scheduled, they may be extended by 3 hours at both ends upon consultation with PI. Exposure_Number: 1 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: Comments: None Exposure_Number: 2 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 800 S Special_Requirements: SAME POS AS 1 Comments: None Exposure_Number: 3 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.3535, 0.3535 Comments: None Exposure_Number: 4 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 3 Comments: None Exposure_Number: 5 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 3 Comments: None Exposure_Number: 6 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.7070, 0.7070 Comments: None Exposure_Number: 7 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 6 Comments: None Exposure_Number: 8 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 6 Comments: None Exposure_Number: 9 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.0605, 1.0605 Comments: None Exposure_Number: 10 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 9 Comments: None Exposure_Number: 11 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 9 Comments: None Exposure_Number: 12 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.414, 1.414 Comments: None Exposure_Number: 13 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 12 Comments: None Exposure_Number: 14 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 12 Comments: None Exposure_Number: 15 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.7675, 1.7675 Comments: None Exposure_Number: 16 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 15 Comments: None Exposure_Number: 17 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 15 Comments: None Exposure_Number: 18 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 2.121, 2.121 Comments: None Exposure_Number: 19 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 18 Comments: None Exposure_Number: 20 Target_Name: COMET-CERNIS-83O1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 18 Comments: None Visit_Number: 02 Visit_Requirements: On_Hold_Comments: Visit_Comments: Windows selected (file spike_6447_2.wnd made by A. Lubenow) so that the field stars do not interfere with observations. The constraints are that there is no object within 5" from the comet's orbit, nor along the orbit for +/- 3 hours, nothing bright in the FOV of the CCD (with diffraction spikes visible), most have at least 6 consecutive hrs of observation, and have a solar elongation greater than 100 deg. The windows should be OR'ed. Note if total scheduling windows are thus too constraining to be scheduled, they may be extended by 3 hours at both ends upon consultation with PI. Exposure_Number: 21 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: Comments: None Exposure_Number: 22 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 800 S Special_Requirements: SAME POS AS 21 Comments: None Exposure_Number: 23 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.3535, 0.3535 Comments: None Exposure_Number: 24 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 23 Comments: None Exposure_Number: 25 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 23 Comments: None Exposure_Number: 26 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.7070, 0.7070 Comments: None Exposure_Number: 27 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 26 Comments: None Exposure_Number: 28 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 26 Comments: None Exposure_Number: 29 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.0605, 1.0605 Comments: None Exposure_Number: 30 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 29 Comments: None Exposure_Number: 31 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 29 Comments: None Exposure_Number: 32 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.414, 1.414 Comments: None Exposure_Number: 33 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 32 Comments: None Exposure_Number: 34 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 32 Comments: None Exposure_Number: 35 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.7675, 1.7675 Comments: None Exposure_Number: 36 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 35 Comments: None Exposure_Number: 37 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 35 Comments: None Exposure_Number: 38 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 2.121, 2.121 Comments: None Exposure_Number: 39 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 38 Comments: None Exposure_Number: 40 Target_Name: COMET-SHOEMAKER-88B1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 38 Comments: None Visit_Number: 03 Visit_Requirements: On_Hold_Comments: Visit_Comments: Windows selected (file spike_6447_3.wnd made by A. Lubenow) so that the field stars do not interfere with observations. The constraints are that there is no object within 5" from the comet's orbit, nor along the orbit for +/- 3 hours, nothing bright in the FOV of the CCD (with diffraction spikes visible), most have at least 6 consecutive hrs of observation, and have a solar elongation greater than 100 deg. The windows should be OR'ed. Note if total scheduling windows are thus too constraining to be scheduled, they may be extended by 3 hours at both ends upon consultation with PI. Exposure_Number: 41 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: Comments: None Exposure_Number: 42 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 800 S Special_Requirements: SAME POS AS 41 Comments: None Exposure_Number: 43 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.3535, 0.3535 Comments: None Exposure_Number: 44 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 43 Comments: None Exposure_Number: 45 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 43 Comments: None Exposure_Number: 46 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 0.7070, 0.7070 Comments: None Exposure_Number: 47 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 46 Comments: None Exposure_Number: 48 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 46 Comments: None Exposure_Number: 49 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.0605, 1.0605 Comments: None Exposure_Number: 50 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 49 Comments: None Exposure_Number: 51 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 49 Comments: None Exposure_Number: 52 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.414, 1.414 Comments: None Exposure_Number: 53 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 52 Comments: None Exposure_Number: 54 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 52 Comments: None Exposure_Number: 55 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 1.7675, 1.7675 Comments: None Exposure_Number: 56 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 55 Comments: None Exposure_Number: 57 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 55 Comments: None Exposure_Number: 58 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1000 S Special_Requirements: POS TARG 2.121, 2.121 Comments: None Exposure_Number: 59 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500 S Special_Requirements: SAME POS AS 58 Comments: None Exposure_Number: 60 Target_Name: COMET-TORRES-87F1 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F675W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 400 S Special_Requirements: SAME POS AS 58 Comments: None 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