!  File:  4193C.PROP
!  Database:  PEPDB
!  Date:  20-FEB-1994:12:46:17

coverpage:

  title_1:         OPPORTUNITY OCCULTATIONS BY SMALL BODIES - CONT OF 1079
    sci_cat:       SOLAR SYSTEM
    proposal_for:  GTO/HSP
    targ_of_opp:   Y
    cont_id:       1079
    pi_fname:      ROBERT
    pi_mi:         C.
    pi_lname:      BLESS
    pi_inst:       WISCONSIN, UNIVERSITY OF
    pi_country:    USA
    pi_phone:      (608)262-1715
    keywords_1:    COMET, ASTEROID, SATELLITE, PLUTO, OCCULTATION
    hours_pri:     1.75
    num_pri:       7
    realtime:      X
    time_crit:     Y
! end of coverpage

abstract:

    line_1:        Although an occultation by any specific comet,
    line_2:        asteroid, satellite, or Pluto is unlikely to be
    line_3:        observable from the ST, the scientific return from
    line_4:        such an event would be great because of the superior
    line_5:        signal-to-noise ratio achievable with the ST for
    line_6:        occultation observations. We propose to observe
    line_7:        occultations by these bodies with the ST, as the
    line_8:        opportunites arise, to probe their atmospheres,
    line_9:        determine their sizes and achieve other goals. With
    line_10:       such diverse possibilities, one must examine each
    line_11:       opportunity as it occurs and formulate an observing
    line_12:       strategy to fit that particular case.  Revision
    line_13:       History:  New targets added, 4/24/92, asb.

!
! end of abstract

general_form_proposers:

  lname:           ROBINSON
    fname:         EDWARD
    mi:            L.
    inst:          TEXAS, UNIVERSITY OF
    country:       USA

!

  lname:           BLESS
    fname:         ROBERT
    mi:            C.
    inst:          WISCONSIN, UNIVERSITY OF
    country:       USA

!

  lname:           VAN CITTERS
    fname:         G.
    mi:            W.
    inst:          NATIONAL SCIENCE FOUNDATION
    country:       USA

!

  lname:           DOLAN
    fname:         JOSEPH
    mi:            F.
    inst:          NASA, GODDARD SPACE FLIGHT CENTER
    country:       USA

!

  lname:           WHITE
    fname:         RICHARD
    mi:            L.
    inst:          SPACE TELESCOPE SCIENCE INSTITUTE
    country:       USA

!

  lname:           ELLIOT
    fname:         JAMES
    mi:            L.
    inst:          MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    country:       USA

!
! end of general_form_proposers block

general_form_text:

  question:        3
    section:       1
    line_1:        We plan to identify those occultations of sufficient
    line_2:        signal-to-noise ratio to achieve the goals outlined
    line_3:        in Section 2. Each observation will require (i)
    line_4:        onboard acquisition to verify the guide stars; (ii)
    line_5:        a scan of about ten arc-seconds along the track that
    line_6:        the object will follow relative to the occulting
    line_7:        body and (iii) a time series run on the object with
    line_8:        whatever filter aperture combination that is chosen
    line_9:        for the observation. For some occultations to be
    line_10:       observed in the far UV, prior multi-filter
    line_11:       photometry of the object will be necessary in order
    line_12:       to determine the most appropriate filter to use for
    line_13:       the occultation. For now, we shall assume that the
    line_14:       calibration and observation time will average about
    line_15:       60 minutes per occultation observed.

!

  question:        4
    section:       1
    line_1:        We can achieve a much better signal-to-noise ratio
    line_2:        for the temperature profiles and other information
    line_3:        than can be obtained for small body occultations
    line_4:        than has been possible from the ground for the
    line_5:        following reasons: (i) the greatly improved
    line_6:        photometric stability of ST photometry, which will
    line_7:        substantially reduce the errors in the numerical
    line_8:        inversion of the data that is necessary to obtain
    line_9:        the temperature profiles; (ii) our ability to reject
    line_10:       background light from the occulting object (such as
    line_11:       a comet ) by employing small focal plane apertures;
    line_12:       and (iii) the absence of scintillation noise, which
    line_13:       has strong components at frequencies comparable to
    line_14:       the occultation timescale.

!

  question:        5
    section:       1
    line_1:        For bodies with possible atmospheres, tracking the
    line_2:        occulted star will require a real time update, due
    line_3:        to its complicated path caused by refraction in the
    line_4:        occulting body's atmosphere and the uncertainties in
    line_5:        predicting the ST orbit.

!

  question:        6
    section:       1
    line_1:        For comets and the larger bodies (Titan, Triton, and
    line_2:        Pluto) a prior scan over 10 arc-seconds is needed to
    line_3:        map the scattered light field, which is needed for
    line_4:        the data reduction.

!

  question:        7
    section:       1
    line_1:        Data will be reduced and analyzed at MIT with VAX
    line_2:        11-750 belonging to the planetary astronomy group.

!

  question:        10
    section:       1
    line_1:        TBD

!

  question:        13
    section:       1
    line_1:        An observation of an occultation by a comet,
    line_2:        asteroid, satellite, or Pluto would yield a variety
    line_3:        of information. For example, we could gain further
    line_4:        information about the atmospheres of Pluto and
    line_5:        Triton, including knowledge of the composition and
    line_6:        structure of their atmospheres.  Also, the presence
    line_7:        of possible material in the neighborhood of an
    line_8:        asteroid could be obtained. Opportunity stellar
    line_9:        occultations by small bodies are proposed to be
    line_10:       observed with the HSP or FOS.

!
!end of general form text

general_form_address:

  lname:           BLESS
    fname:         ROBERT
    mi:            C.
    category:      PI
    inst:          UNIVERSITY OF WISCONSIN
    addr_1:        DEPARTMENT OF ASTRONOMY
    addr_2:        475 NORTH CHARTER STREET
    city:          MADISON
    state:         WI
    zip:           53706
    country:       USA
    phone:         608-262-1715

!
! end of general_form_address records

fixed_targets:

    targnum:       10
    name_1:        GSC6349-01493
    descr_1:       STAR TO BE OCCULTED TWICE BY TITAN.
    descr_2:       CLOSE APPROACHES AT 7-OCT-92:08:59,
    descr_3:       AND 9-OCT-92:05:07.
    pos_1:         PLATE-ID = 018A,
    pos_2:         RA = 20H 58M 46.997S +/- 0.03",
    pos_3:         DEC = -18D 11' 32.52" +/- 0.05"
    equinox:       J2000
    acqpr_1:       BKG
    comment_5:     SOLAR ELONG 117D
    fluxnum_1:     1
    fluxval_1:     B = 13.8 +/- 0.6

!

    targnum:       11
    name_1:        01493-OFFSET
    name_2:        GSC6349-01494
    descr_1:       OFFSET TARGET FOR GSC6349-01493
    pos_1:         PLATE-ID = 018A,
    pos_2:         RA = 20H 58M 46.494S +/- 0.06",
    pos_3:         DEC = -18D 10' 23.34" +/- 0.05"
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     B = 15.5 +/- 0.6

!
! end of fixed targets

solar_system_targets:

  targnum:         12
    name_1:        01493-A-BACKGROUND
    descr_1:       OFFSET TITAN
    lev1_1:        STD = TITAN
    lev2_1:        TYPE = POS_ANGLE,
    lev2_2:        RAD = 25.5,
    lev2_3:        ANG = 98.8,
    lev2_4:        REF = NORTH
    comment_1:     FOR USE IN A SCAN OF
    comment_2:     BACKGROUND LEVELS ALONG
    comment_3:     THE PATH OF THE OCCULTED STAR

!

  targnum:         13
    name_1:        01493-B-BACKGROUND
    descr_1:       OFFSET TITAN
    lev1_1:        STD = TITAN
    lev2_1:        TYPE = POS_ANGLE,
    lev2_2:        RAD = 25.5,
    lev2_3:        ANG = 106.0,
    lev2_4:        REF = NORTH
    comment_1:     FOR USE IN A SCAN OF
    comment_2:     BACKGROUND LEVELS ALONG
    comment_3:     THE PATH OF THE OCCULTED STAR

!

  targnum:         14
    name_1:        TITAN-CENTER
    descr_1:       SATELLITE TITAN
    lev1_1:        STD = TITAN, ACQ = 0.1
    comment_1:     ACQUISITION TARGET FOR
    comment_2:     BACKGROUND SCANS
    fluxnum_1:     1
    fluxval_1:     V = 8.3 +/- 0.5

!
! end of solar system targets

! No generic target records found

exposure_logsheet:

    linenum:       4.000
    sequence_1:    DEFINE
    sequence_2:    ONBRD-ACQ
    targname:      #
    config:        HSP/VIS
    opmode:        ACQ
    num_exp:       1
    time_per_exp:  1S
    fluxnum_1:     1
    priority:      1

!

    linenum:       6.000
    sequence_1:    DEFINE
    sequence_2:    BACK-SCAN
    targname:      #
    config:        HSP/PMT/VIS
    opmode:        SPLIT
    aperture:      1.0
    sp_element:    F750W/F320N
    num_exp:       1
    time_per_exp:  1S
    fluxnum_1:     1
    priority:      1
    param_1:       #
    req_1:         SPATIAL SCAN;

!

    linenum:       7.000
    sequence_1:    DEFINE
    sequence_2:    OCC
    targname:      #
    config:        HSP/PMT/VIS
    opmode:        SPLIT
    aperture:      1.0
    sp_element:    F750W/F320N
    num_exp:       1
    time_per_exp:  1M
    fluxnum_1:     1
    priority:      1
    param_1:       #
    req_1:         CRIT OBS;

!

    linenum:       10.000
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      TITAN-CENTER
    time_per_exp:  X1
    req_1:         ONBOARD ACQ FOR 10.01;
    req_2:         SEQ 10.00 - 10.01 NO GAP;

!

    linenum:       10.010
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         SEQ 10.01 - 10.03;
    req_2:         GROUP 10.01 - 10.04 WITHIN 9H;
    req_3:         CYCLE 2/10.00 - 10.28;

!

    linenum:       10.020
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       10.030
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       10.040
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      01493-OFFSET
    time_per_exp:  X120
    req_1:         ONBOARD ACQ FOR 10.10 - 10.28;
    req_2:         SEQ 10.04 - 10.10 NO GAP;

!

    linenum:       10.100
    sequence_1:    USE
    sequence_2:    OCC
    targname:      GSC6349-01493
    time_per_exp:  X30
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         AT 7-OCT-92:08:45 +/- 1M;
    comment_1:     END EXPOSURE AT 7-OCT-92:09:14.

!

    linenum:       10.250
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      TITAN-CENTER
    time_per_exp:  X1
    req_1:         ONBOARD ACQ FOR 10.260;

!

    linenum:       10.260
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         SEQ 10.26 - 10.28;
    req_2:         GROUP 10.10 - 10.28 WITHIN 9H;

!

    linenum:       10.270
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       10.280
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-A-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       11.000
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      TITAN-CENTER
    time_per_exp:  X1
    req_1:         ONBOARD ACQ FOR 11.01;
    req_2:         SEQ 11.00 - 11.01 NO GAP;

!

    linenum:       11.010
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         SEQ 11.01 - 11.03;
    req_2:         GROUP 11.01 - 11.04 WITHIN 9H;
    req_3:         CYCLE 2/11.00 - 11.28;

!

    linenum:       11.020
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       11.030
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       11.040
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      01493-OFFSET
    time_per_exp:  X120
    req_1:         ONBOARD ACQ FOR 11.10 - 11.28;
    req_2:         SEQ 11.04 - 11.10 NO GAP;

!

    linenum:       11.100
    sequence_1:    USE
    sequence_2:    OCC
    targname:      GSC6349-01493
    time_per_exp:  X30
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         AT 9-OCT-92:04:53 +/- 1M;
    comment_1:     END EXPOSURE AT 9-OCT-92:05:22.

!

    linenum:       11.250
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      TITAN-CENTER
    time_per_exp:  X1
    req_1:         ONBOARD ACQ FOR 11.260;

!

    linenum:       11.260
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,
    req_1:         SEQ 11.26 - 11.28;
    req_2:         GROUP 11.10 - 11.28 WITHIN 9H;

!

    linenum:       11.270
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!

    linenum:       11.280
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      01493-B-BACKGROUND
    time_per_exp:  X200
    param_1:       SAMPLE-TIME = 0.05,
    param_2:       PRECISION = HIGH,
    param_3:       DATA-FORMAT = ALL,
    param_4:       PMT-ANALOG = 1000,
    param_5:       VIS-ANALOG = 10,

!
! end of exposure logsheet

scan_data:

    line_list:     10.01, 10.03, 10.26, 10.28
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       0.0000
    scan_length:     37.5000
    sides_angle:    90.0000
    number_lines:  1
    scan_rate:       0.0750
    first_line_pa: 278.8000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    0

!

    line_list:     10.02, 10.27
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       2.0000
    scan_length:     37.5000
    sides_angle:    90.0000
    number_lines:  3
    scan_rate:       0.0750
    first_line_pa: 278.8000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    1.0

!

    line_list:     11.01, 11.03, 11.26, 11.28
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       0.0000
    scan_length:     37.5000
    sides_angle:    90.0000
    number_lines:  1
    scan_rate:       0.0750
    first_line_pa: 286.0000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    0

!

    line_list:     11.02, 11.27
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       2.0000
    scan_length:     37.5000
    sides_angle:    90.0000
    number_lines:  3
    scan_rate:       0.0750
    first_line_pa: 286.0000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    1.0

!
! end of scan data