! File: 2657C.PROP ! Database: PEPDB ! Date: 17-FEB-1994:09:59:58 coverpage: title_1: HIGH RESOLUTION SPECTROSCOPY OF COMETS sci_cat: SOLAR SYSTEM sci_subcat: COMET proposal_for: GO targ_of_opp: X pi_title: P.I. pi_fname: MICHAEL pi_mi: F. pi_lname: A'HEARN pi_inst: MARYLAND, UNIVERSITY OF pi_country: USA pi_phone: 301-454-6076 keywords_1: COMETS hours_pri: 4.75 num_pri: 1 hrs: X realtime: X time_crit: X funds_amount: 106584 funds_length: 12 funds_date: NOV-90 pi_position: PROFESSOR off_fname: VICTOR off_lname: MEDINA off_title: DIRECTOR off_inst: THE UNIVERSITY OF MARYLAND off_addr_1: THE UNIVERSITY OF MARYLAND off_addr_2: OFFICE OF SPONSORED PROGRAMS off_city: COLLEGE PARK off_state: MD off_zip: 20742 off_country: USA off_phone: 301-454-3117 ! end of coverpage abstract: line_1: We propose to observe comets at high spectral resolution in order to search for line_2: isotopic variants and in order to elucidate the emission mechanism of the line_3: various molecular species that are known. This knowledge of the emission line_4: mechanism is critical to interpreting observed fluxes from comets in terms of line_5: abundances which in turn provide our best clues to the conditions of line_6: temperature and pressure in the solar nebula. ! ! end of abstract general_form_proposers: lname: A'HEARN fname: MICHAEL title: DR. mi: F. inst: MARYLAND, UNIVERSITY OF country: USA ! lname: ARPIGNY fname: CLAUDE title: DR. inst: LIEGE UNIVERSITY country: BELGIUM esa: X ! lname: BERTAUX fname: JEAN-LOUP title: DR. inst: CNRS, DEPARTMENT OF AERONOMY country: FRANCE esa: X ! lname: FELDMAN fname: PAUL title: DR. mi: D. inst: JOHNS HOPKINS UNIVERSITY country: USA ! lname: KIM fname: SANG title: DR. mi: J. inst: MARYLAND, UNIVERSITY OF country: USA ! lname: LUTZ fname: BARRY title: DR. mi: L. inst: LOWELL OBSERVATORY country: USA ! lname: SCHLEICHER fname: DAVID title: DR. mi: G. inst: LOWELL OBSERVATORY country: USA ! lname: WEAVER fname: HAROLD title: DR. mi: A. inst: STSCI country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: Because of uncertainties in the ephemerides of comets as well as line_2: uncertainties regarding HST's abilities to track moving targets, we propose to line_3: use WF/PC images (WF mode) to locate the photocenter of the comet on the first line_4: visit to the comet. Succeding visits can then be handled with the FOS line_5: internal acquisition function with a handover to HRS. A WFC image will be taken line_6: after each HRS exposure to confirm tracking. Exposure times assume line_7: a comet meeting but not exceding the TO criterion. line_9: a. Oxygen isotopes in OH: Large science aperture (spatial resolution not line_10: important, pointing not critical); echelle-B, order 20 centered near 2830, line_11: m*lambda = 56,600. Exposure = 45 min. line_13: b. Prompt emission of OH: Large science aperture for maximum sensitivity to line_14: weak lines from extended source. G270M centered at 3095A since line_15: resolution adequate. Centered on nucleus. Exposure time 10 minutes. line_16: This directly detects excited rotational states. Offset by 2 arcsec. line_17: Exposure time 15 minutes to measure change in lambda doublet population line_18: with distance from nucleus. Offset by 4 arcsec for same goal. Exposure line_19: time 20 minutes. Small science aperture centered on nucleus to determine line_20: inversion closest to nucleus. Exposure time 100 minutes. line_22: c . CS: Small science aperture; grating G270M centered at 2578. Large line_23: science aperture, echelle-B, order 22, centered at m*lambda = 56,700. Both ! question: 3 section: 2 line_1: exposures on photocenter sample, on average, very different distances from line_2: nucleus with maximum sensitivity and comparable (2.5x) resolution. line_3: SSA/G270M requires 100 min, LSA/ECH-B requires 40 min. ! question: 6 section: 1 line_1: This is a target of opportunity program to be activated upon the appearance line_2: of a suitable comet. Occasionally periodic comets meet the criterion for our line_3: TO. Comet P/Honda-Mrkos-Padjusakova meets the criterion for our TO during the line_4: nominal proposal period but will not be available in the 'actual' observing line_5: window. Once the actual observing window is known, periodic comets will be line_6: searched for a suitable target. Since ephemerides of comets are poorly line_7: known and since this proposal requires an accurate centering relative to the line_8: photocenter of the comet, WF/PC real time acquisition is needed for the first line_9: visit to the comet unless this program is executed immediately following one line_10: of the other cometary TO programs. Subsequent visits can be made without line_11: real-time acquisition using the FOS internal acquisition mode. Certain aspects line_12: of the program (prompt emission of OH) require scheduling at certain line_13: heliocentric radial velocities in order that the physically relevant processes line_14: can be detected. ! question: 8 section: 1 line_1: Criterion: Q(H2O) > 10**29 * r**2 * delta line_2: Our experience with IUE shows that targets of opportunity are frequent. line_3: We have averaged approximately 1.5 target of opportunity comets per year over line_4: 11 years of work with IUE. The criteria for this HST proposal are much more line_5: stringent since we do not propose to do work that can still be done with IUE. line_6: In 11 years with IUE, 7 comets satisfied this criterion so we expect a suitable line_7: target of opportunity once every year or two. line_8: The list of periodic comets will be searched when the actual line_9: observing window is known. ! !end of general form text general_form_address: lname: A'HEARN fname: MICHAEL mi: F. title: DR. category: PI inst: UNIVERSITY OF MARYLAND addr_1: ASTRONOMY PROGRAM addr_2: BLDG. 224 RM. 1243 city: COLLEGE PARK state: MD zip: 20742 country: USA ! ! end of general_form_address records ! No fixed target records found ! No solar system records found generic_targets: targnum_1: 1 name_1: COMET-TBD descr_1: COMET TARGET OF OPPORTUNITY criteria_1: THE WATER PRODUCTION RATE > 2.0E29*(R**2)*DELTA PER SECOND criteria_2: R=HELIOCENTRIC DISTANCE AND DELTA=GEOCENTRIC DISTANCE (IN AU) criteria_3: SOLAR ELONGATION > 50 DEGREES acqpr_1: EXT comment_1: FLUX ESTIMATES FOR COMET BARELY comment_2: MEETING TO CRITERION. FLUXES BASED comment_3: ON PREVIOUS IUE MEASUREMENTS. comment_4: THESE EMISSIONS ARE VARIABLE FROM comment_5: COMET TO COMET AND WITH HELIO- comment_6: CENTRIC AND GEOCENTRIC DISTANCES. fluxnum_1: 1 fluxval_1: SURF(V) = 12 +/- 1 fluxnum_2: 2 fluxval_2: SURF-LINE(3095) = 2.5 +/- 1.5 E-14 fluxnum_3: 3 fluxval_3: W-LINE(3095) = 1.0 +/- 0.2 fluxnum_4: 4 fluxval_4: SURF-LINE(3085) = 1.3 +/- 0.3 E-12 fluxnum_5: 5 fluxval_5: W-LINE(3085) = 1.0 +/- 0.2 fluxnum_6: 6 fluxval_6: SURF-LINE(2830) = 1.3 +/- .3 E-15 fluxnum_7: 7 fluxval_7: W-LINE(2830) = 1.0 +/- 0.2 fluxnum_8: 8 fluxval_8: SURF-LINE(2578) = 2.0 +/- 0.5 E-13 fluxnum_9: 9 fluxval_9: W-LINE(2578) = 1.0 +/- 0.2 ! targnum_1: 2 name_1: COMET-TBD-2ARCSEC descr_1: COMET TARGET OF OPPORTUNITY descr_2: OFFSET FROM NUCLEUS 2 ARCSEC TOWARD SUN criteria_1: ^ acqpr_1: ^ comment_1: ^ fluxnum_1: 1 fluxval_1: SURF(V) = 12 +/- 1 fluxnum_2: 2 fluxval_2: SURF-LINE(3095) = 1.5 +/- 0.5 E-14 fluxnum_3: 3 fluxval_3: W-LINE(3095) = 1.0 +/- 0.2 fluxnum_4: 4 fluxval_4: SURF-LINE(3085) = 1.3 +/- 0.3 E-12 fluxnum_5: 5 fluxval_5: W-LINE(3085) = 1.0 +/- 0.2 fluxnum_6: 6 fluxval_6: SURF-LINE(2830) = 1.3 +/- .3 E-15 fluxnum_7: 7 fluxval_7: W-LINE(2830) = 1.0 +/- 0.2 fluxnum_8: 8 fluxval_8: SURF-LINE(2578) = 0.5 +/- 0.2 E-13 fluxnum_9: 9 fluxval_9: W-LINE(2578) = 1.0 +/- 0.2 ! targnum_1: 3 name_1: COMET-TBD-4ARCSEC descr_1: COMET TARGET OF OPPORTUNITY descr_2: OFFSET FROM NUCLEUS 4 ARC-SEC TO SUN criteria_1: ^ acqpr_1: ^ comment_1: ^ fluxnum_1: 1 fluxval_1: SURF(V) = 12 +/- 1 fluxnum_2: 2 fluxval_2: SURF-LINE(3095) = 0.5 +/- 0.2 E-14 fluxnum_3: 3 fluxval_3: W-LINE(3095) = 1.0 +/- 0.2 fluxnum_4: 4 fluxval_4: SURF-LINE(3085) = 1.3 +/- 0.3 E-12 fluxnum_5: 5 fluxval_5: W-LINE(3085) = 1.0 +/- 0.2 fluxnum_6: 6 fluxval_6: SURF-LINE(2830) = 1.3 +/- .3 E-15 fluxnum_7: 7 fluxval_7: W-LINE(2830) = 1.0 +/- 0.2 fluxnum_8: 8 fluxval_8: SURF-LINE(2578) = 0.2 +/- 0.05 E-13 fluxnum_9: 9 fluxval_9: W-LINE(2578) = 1.0 +/- 0.2 ! ! end of generic targets exposure_logsheet: linenum: 1.000 targname: COMET-TBD config: WFC opmode: IMAGE aperture: ALL sp_element: F791W num_exp: 1 time_per_exp: 1S fluxnum_1: 1 priority: 1 req_1: INT ACQ FOR 2; req_2: SEQ 1-12 NO GAP; req_3: TARG OF OPP / 1-12 comment_1: THIS EXPOSURE OMITTED IF comment_2: IMMEDIATELY PRECEDING EXPOSURE comment_3: WAS FROM P2442 OR P2483 comment_4: SEQ 1-12 CAN BE INTERLEAVED comment_5: WITH EXPOSURES FROM P2442 comment_6: AND P2483 ! linenum: 2.000 targname: ^ config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 3095 num_exp: 1 time_per_exp: 8M s_to_n: 10 s_to_n_time: 5M fluxnum_1: 2,3 priority: 2 req_1: SEQ 2-5 NON-INT comment_1: ADJUST TIME_PER_EXP FOR comment_2: SEQ 2-5 TO FILL ORBIT ! linenum: 3.000 targname: COMET-TBD-2ARCSEC config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 3095 num_exp: 1 time_per_exp: 10M s_to_n: 10 s_to_n_time: 8M fluxnum_1: 2,3 priority: 2 req_1: NON-INT / 2-5 comment_1: OFFSET 2 ARCSEC FROM NUCLEUS TO SUN ! linenum: 4.000 targname: COMET-TBD-4ARCSEC config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 3095 num_exp: 1 time_per_exp: 15M s_to_n: 10 s_to_n_time: 12M fluxnum_1: 2,3 priority: 2 req_1: NON-INT / 2-5 comment_1: OFFSET 4 ARCSEC FROM NUCLEUS TO SUN ! linenum: 5.000 targname: ^ config: WFC opmode: IMAGE aperture: ALL sp_element: F791W num_exp: 1 time_per_exp: 1S fluxnum_1: 1 priority: 4 req_1: NON-INT / 2-5 comment_1: MANEUVER UNDER GYROHOLD AFTER HRS comment_2: EXPOSURE TO VERIFY POINTING ! linenum: 6.000 targname: COMET-TBD config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-B wavelength: 2830 num_exp: 1 time_per_exp: 35M s_to_n: 3 s_to_n_time: 22M fluxnum_1: 6,7 priority: 1 comment_1: USE GYROHOLD TO FINISH EXPOSURE comment_2: WHEN GUIDE STARS ARE LOST ! linenum: 7.000 targname: ^ config: WFC opmode: IMAGE aperture: ALL sp_element: F791W num_exp: 1 time_per_exp: 1S fluxnum_1: 1 priority: 4 req_1: SEQ 6-7 NON-INT comment_1: MANEUVER UNDER GYROHOLD AFTER HRS comment_2: EXPOSURE TO VERIFY POINTING ! linenum: 8.000 targname: ^ config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2578 num_exp: 1 time_per_exp: 32M s_to_n: 10 s_to_n_time: 20M fluxnum_1: 8,9 priority: 3 comment_1: USE GYROHOLD TO FINISH EXPOSURE comment_2: WHEN GUIDE STARS ARE LOST ! linenum: 9.000 targname: ^ config: WFC opmode: IMAGE aperture: ALL sp_element: F791W num_exp: 1 time_per_exp: 1S fluxnum_1: 1 priority: 4 req_1: SEQ 8-9 NON-INT comment_1: MANEUVER UNDER GYROHOLD AFTER HRS comment_2: EXPOSURE TO VERIFY POINTING ! linenum: 10.000 targname: COMET-TBD config: FOS/RD opmode: ACQ/FIRMWARE aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 1.4S priority: 3 param_1: MAP=BOTH param_2: BRIGHT=480000 param_3: FAINT=4800 req_1: ONBOARD ACQ FOR 11 ! linenum: 11.000 targname: ^ config: HRS opmode: ACCUM aperture: 0.25 sp_element: G270M wavelength: 2578 num_exp: 1 time_per_exp: 50M s_to_n: 10 s_to_n_time: 50M fluxnum_1: 8,9 priority: 3 ! linenum: 12.000 targname: ^ config: WFC opmode: IMAGE aperture: ALL sp_element: F791W num_exp: 1 time_per_exp: 1S fluxnum_1: 1 priority: 4 req_1: SEQ 11-12 NON-INT comment_1: MANEUVER UNDER GYROHOLD AFTER HRS comment_2: EXPOSURE TO VERIFY POINTING ! ! end of exposure logsheet ! No scan data records found