!  File:  3095C.PROP
!  Database:  PEPDB
!  Date:  18-FEB-1994:16:47:51

coverpage:

  title_1:         WHITE DWARF PULSATIONS AND DIFFUSION--INDUCED CN BURNING
    sci_cat:       STELLAR ASTROPHYSICS
    proposal_for:  EROS
    pi_fname:      JOSEPH
    pi_lname:      DOLAN
    pi_inst:       STANFORD UNIVERSITY
    pi_country:    USA
    pi_phone:      (415)723-2464
    keywords_1:    WHITE DWARFS: PULSATIONS
    hours_pri:     1.00
    num_pri:       1
    realtime:      N
! end of coverpage

abstract:

    line_1:        We propose to observe the DA-type white dwarf Sirius B to search for non-
    line_2:        radial pulsations which have been predicted and recently found in other
    line_3:        classes of white dwarfs.  Theory predicts that pulsations caused by
    line_4:        diffusion-induced CN burning should exist in this class of white dwarf.
    line_5:        Such pulsations would constitute useful probes of the internal structure
    line_6:        of these stars, and may reveal the importance of nucleosynthesis in the
    line_7:        white dwarf stage of stellar evolution.  Pulsational activity, if found,
    line_8:        may also be related to the controversial but possibly real color change of
    line_9:        Sirius, from a recorded color of red in Ptolemy's time to its present blue-
    line_10:       white color.  In one scenario, a thermonuclear runaway would temporarily
    line_11:       expand Sirius B to a red giant, followed by a return to the white dwarf
    line_12:       stage.  Regardless of the interpretation of its historical record, Sirius
    line_13:       B is an ideal candidate in which to search for pulsations driven by
    line_14:       diffusion-induced CN burning.
    line_15:       REVISION HISTORY:  Created base line version--BJW 9/11/90;

!
! end of abstract

general_form_proposers:

  lname:           DOLAN
    fname:         JOSEPH
    mi:            F.
    inst:          STANFORD UNIVERSITY
    country:       USA

!

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

!
! end of general_form_proposers block

general_form_text:

  question:        3
    section:       1
    line_1:        The DA-type white dwarf Sirius B is proposed as a target.  A 0.5 hour
    line_2:        exposure will be taken with the HSP using the UV2 prism.  Two filter
    line_3:        bandpasses are used quasi-simultaneously:  F145M, close to the wavelength
    line_4:        of peak flux in the star (but longward of the broad Lyman alpha absorption
    line_5:        line), and F262M, to allow us to derive color temperatures of the star
    line_6:        through any pulsation.  Integration time will be one second in one filter,
    line_7:        then one second in the other, repeating throughout the observation.
    line_8:        Multiple mode pulsations often interfere destructively, leading to intervals
    line_9:        of very low amplitude variability.  Each star will be observed twice to
    line_10:       determine whether the amplitude of any pulsation is variable in time.

!
!end of general form text

general_form_address:

  lname:           DOLAN
    fname:         JOSEPH
    category:      PI
    inst:          STANFORD UNIVERSITY

!

  lname:           DOLAN
    fname:         JOSEPH
    mi:            F.
    category:      PI
    inst:          STANFORD UNIVERSITY
    addr_1:        DEPT. OF PHYSICS
    city:          STANFORD
    state:         CA
    zip:           94305
    country:       USA
    phone:         (415)723-2464

!

  lname:           BLESS
    fname:         ROBERT
    mi:            C
    category:      CON
    inst:          UNIVERSITY OF WISCONSIN
    addr_1:        SPACE ASTRONOMY LAB
    addr_2:        1150 UNIVERSITY AVE.
    city:          MADISON
    state:         WI
    zip:           53706
    country:       USA
    phone:         (608)262-1715

!
! end of general_form_address records

fixed_targets:

    targnum:       1
    name_1:        SIRIUS-B
    pos_1:         RA = 06H 42M 56.7S +/- 0.2S,
    pos_2:         DEC = -16D 38' 46.4" +/- 0.3"
    equinox:       1950
    fluxnum_1:     1
    fluxval_1:     V=8.5

!
! end of fixed targets

! No solar system records found

! No generic target records found

exposure_logsheet:

    linenum:       1.000
    targname:      SIRIUS-B
    config:        HSP/UV2
    opmode:        ACQ
    num_exp:       1
    time_per_exp:  4S
    fluxnum_1:     1
    priority:      1
    req_1:         INT ACQ FOR 2;

!

    linenum:       2.000
    targname:      ^
    config:        HSP/UV2
    opmode:        PRISM
    aperture:      1.0
    sp_element:    F262M/F145M
    num_exp:       2
    time_per_exp:  30M
    fluxnum_1:     ^
    priority:      ^
    comment_1:     CLOSE BINARY.
    comment_2:     USE MAXIMUM AMOUNT OF TIME
    comment_3:     POSSIBLE IN TWO ORBITS.

!
! end of exposure logsheet

! No scan data records found