!  File:  1085C.PROP
!  Database:  PEPDB
!  Date:  16-FEB-1994:01:07:40

coverpage:

  title_1:         ROTATION PERIODS OF COMETARY NUCLEI
    sci_cat:       SOLAR SYSTEM
    sci_subcat:    COMETS
    proposal_for:  GTO/HSP
    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 NUCLEI, LIGHT CURVE, ROTATION PERIODS
    hours_pri:     10.00
    num_pri:       2
! end of coverpage

abstract:

    line_1:        Comets are thought to be samples of primordial materials from which the solar
    line_2:        system formed that have been stored in the Oort cloud, undisturbed from their
    line_3:        original state, since the planets accreted (4.6 billion years ago).  The
    line_4:        rotation period of a cometary nucleus is a fundamental parameter that
    line_5:        influences the heat budget, which in turn controls the sublimation rate of ice
    line_6:        and dust from the nucleus.  Rotation periods of cometary nuclei have proven
    line_7:        difficult to measure from Earth because of the interferring influence of the
    line_8:        coma.  The solution is to search for periodicities in the comet's light curve
    line_9:        when it is far enough from Earth to be inactive.  We propose to observe a
    line_10:       distant comet and comet Halley for a total of 4 hours each in order to
    line_11:       establish these rotation periods.

!
! 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:        The nuclei of Comet Halley and another distant comet will be observed for a
    line_2:        total of 4 (four) hours each, spread over a period of 30-50 hours, in order to
    line_3:        establish their rotation periods.

!

  question:        4
    section:       1
    line_1:        Precise photometry of faint cometary nuclei has not been highly successful from
    line_2:        Earth.

!

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

!

  question:        10
    section:       1
    line_1:        TBD

!

  question:        13
    section:       1
    line_1:        Observing comet Halley and another comet (TBD) when distant enough from the sun
    line_2:        to be inactive with the HSP over a period of time will establish its light
    line_3:        curve, from which its rotation period can be derived if the nucleus has albedo
    line_4:        features and/or a non-spherical shape, and its rotation axis is not parallel to
    line_5:        the line of sight.

!
!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
    city:          MADISON
    state:         WI
    zip:           53706
    country:       USA
    phone:         608-262-1715

!

  lname:           ELLIOT
    fname:         JAMES
    mi:            L.
    category:      CON
    inst:          MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    addr_1:        BLDG. 54-422
    city:          CAMBRIDGE
    state:         MA
    zip:           02139
    country:       USA
    phone:         617-253-6308
    telex:         921473 MIT CAM

!
! end of general_form_address records

! No fixed target records found

solar_system_targets:

  targnum:         2
    name_1:        HALLEY
    descr_1:       COMET HALLEY NUCLEUS WHEN NOT HIGHLY ACTIV
    descr_2:       E
    lev1_1:        JPL EPHEMERIS
    fluxnum_1:     1
    fluxval_1:     V=18+/-4

!
! end of solar system targets

generic_targets:

  targnum_1:       1
    name_1:        COMET-NUC
    descr_1:       NUCLEUS OF AN INACTIVE COMET
    criteria_1:    INACTIVE COMET NUCLEUS SELECTED BY GTO
    fluxnum_1:     1
    fluxval_1:     V=17+/-3

!
! end of generic targets

exposure_logsheet:

    linenum:       1.000
    sequence_1:    DEFINE
    sequence_2:    HSP-SER
    targname:      #
    config:        HSP/ACQ
    opmode:        ACQ
    aperture:      10
    sp_element:    CLEAR
    num_exp:       1
    time_per_exp:  5 M
    s_to_n:        5
    s_to_n_time:   1S
    fluxnum_1:     1
    priority:      2
    req_1:         ONBOARD ACQ FOR 2

!

    linenum:       2.000
    sequence_1:    ^
    targname:      ^
    config:        HSP/PHOT
    opmode:        1APER
    aperture:      0.4
    sp_element:    F400LP
    num_exp:       1
    time_per_exp:  40M
    s_to_n:        50
    s_to_n_time:   1S
    fluxnum_1:     1
    priority:      2
    req_1:         REPEAT 2 EVERY 7H +/- 2H FOR 5 MORE
    req_2:         TIMES

!

    linenum:       3.000
    sequence_1:    USE
    sequence_2:    HSP-SER
    targname:      HALLEY

!

    linenum:       4.000
    sequence_1:    USE
    sequence_2:    HSP-SER
    targname:      COMET-NUC

!
! end of exposure logsheet

! No scan data records found