!  File:  1291C.PROP
!  Database:  PEPDB
!  Date:  16-FEB-1994:10:53:41

coverpage:

  title_1:         COMET HALLEY HYDROGEN CORONA
    sci_cat:       SOLAR SYSTEM
    sci_subcat:    COMETS
    proposal_for:  GTO/OS
    pi_fname:      JOHN
    pi_mi:         J.
    pi_lname:      CALDWELL
    pi_inst:       YORK UNIVERSITY
    pi_country:    CANADA
    pi_phone:      (416) 736-2100 X7721
    keywords_1:    COMET HALLEY, HYDROGEN CORONA, LYMAN ALPHA
    hours_pri:     0.50
    num_pri:       1
    pi_position:   PROFESSOR
! end of coverpage

abstract:

    line_1:        The red leak will be a major problem for most attempts at planetary imaging
    line_2:        with the WF/PC using the Lyman alpha filter. However, for comets, the OAO-2
    line_3:        discovered a very extended corona consisting of atomic H. Thedetection was
    line_4:        possible because of the strong Lyman alpha signal due to resonant scattering of
    line_5:        the Solar feature at that wavelength. For comets, the red leak would grossly
    line_6:        distort the image of the near-nuclear region, but will not effect the extended
    line_7:        atmosphere very much. As comet Halley recedes in 1986-87, the HST should be
    line_8:        uniquely able to monitor the final stages of its activity.

!
! end of abstract

general_form_proposers:

  lname:           CALDWELL
    fname:         JOHN
    mi:            J.
    inst:          YORK UNIVERSITY
    country:       CANADA

!
! end of general_form_proposers block

general_form_text:

  question:        3
    section:       0
    line_1:        This proposal consists of a single exposure, which should be made as soon after
    line_2:        ST launch as possible. It requires only a rudimentary tracking capability. It
    line_3:        is not sensitive to red leak problems. The nucleus will certainly be
    line_4:        over-exposed because of the red leak there, but that should not hurt the
    line_5:        coronal observations. There is no red leak in the corona because the Lyman
    line_6:        alpha emission is the strongest feature inthe spectrum of the corona.

!

  question:        3
    section:       1
    line_1:
    line_9:        comment continuation fronm CP section 11 Sepcial Requirements: "Observe as soon
    line_10:       as possible, unless GTO extends to 2060"
    line_12:       comment continutation from EL Page 4, Line 1: Observation should be made as
    line_13:       soon as possible.

!

  question:        4
    section:       0
    line_1:        The ST is needed because it is the most sensitive instrument available which
    line_2:        can image at 1200 A. Ground-based observations are not relevant.

!

  question:        5
    section:       0
    line_1:        The only special scheduling requirement is that it be done as soon as possible,
    line_2:        preferably immediately after the WF/PC is turned on.

!

  question:        6
    section:       0
    line_1:        DARK TIME IS REQUIRED BECAUSE THE SKY IS EXTREMELY BRIGHT IN LYMAN ALPHA DURING
    line_2:        ORBITAL DAYTIME.

!

  question:        7
    section:       0
    line_1:        The image will be examined for excess hydrogen emission near the nucleus.

!

  question:        8
    section:       0
    line_1:        A parallel ST observation of the sky near the comet is being planned.

!

  question:        10
    section:       0
    line_1:        We have access to a VAX computer in the Engineering Department of
    line_2:        SUNY to supplement the resources of the ST ScI.

!

  question:        13
    section:       1
    line_1:        A WFC Lyman alpha exposure of Comet Halley will be obtained as soon as possible
    line_2:        after HST launch to monitor atomic H coronal acitivity as the comet recedes.
    line_3:        The red leak should not be a problem for this observation, because only the
    line_4:        nucleus will be affected.

!
!end of general form text

general_form_address:

  lname:           CALDWELL
    fname:         JOHN
    mi:            J.
    title:         DR.
    category:      PI
    inst:          YORK UNIVERSITY
    addr_1:        PHYSICS DEPT.
    addr_2:        4700 KEELE ST.
    city:          NORTH YORK
    state:         ON
    zip:           M3J 1P3
    country:       CANADA

!
! end of general_form_address records

! No fixed target records found

solar_system_targets:

  targnum:         1
    name_1:        COMET-HALLEY
    descr_1:       COMET HALLEY
    lev1_1:        STD = HALLEY
    comment_1:     TRK = 0.1

!
! end of solar system targets

! No generic target records found

exposure_logsheet:

    linenum:       1.000
    targname:      COMET-HALLEY
    config:        WFC
    opmode:        IMAGE
    aperture:      ALL
    sp_element:    F122M
    num_exp:       1
    time_per_exp:  30M
    priority:      1
    param_1:       PURGE=YES
    req_1:         DARK TIME; POS TARG +4, +4;
    req_2:         CYCLE 2

!
! end of exposure logsheet

! No scan data records found