!   $Id: 5641,v 13.1 1994/07/27 20:00:22 pepsa Exp $
coverpage:
  title_1:         OBSERVATIONS OF MINOR PLANETS AT CROSSING POINTS
    title_2:       PART 1, CYCLE 4, HIGH
    sci_cat:       SOLAR SYSTEM
    sci_subcat:    MINOR PLANETS
    proposal_for:  GTO/AST
    pi_fname:      WILLIAM
    pi_mi:         H.
    pi_lname:      JEFFERYS
    pi_inst:       UNIVERSITY OF TEXAS AT AUSTIN
    pi_country:    USA
    hours_pri:     0.67
    num_pri:       1
    fgs:           Y
    time_crit:     Y
abstract:
    line_1:        Observations of moving solar system objects in POS mode with
    line_2:        the FGSs have the potential of improving the angular accuracy
    line_3:        of such measurements by an order of magnitude over ground- based
    line_4:        measurements.  Such measurements would provide the most accurate
    line_5:        plate scale determination for HST, as well as improve the
    line_6:        determination of the motions of such objects for both orbital
    line_7:        and solar system gravity field determinations.
    line_8:        We will measure the FGS Astrometer Plate Scale
    line_9:        by observing a target minor planet as it traverses the FGS
    line_10:       Astrometer Field of View.  The measuring precision is expected
    line_11:       to be better than a milliarcsecond.  The derived plate scale is
    line_12:       expected to be accurate to a few milliarcseconds over the length
    line_13:       of the pickle, limited by knowledge of the ephemeris motion.
    line_14:       Continuing ground-based observations are being made to provide
    line_15:       the necessary updated ephemeris.

general_form_proposers:
  lname:           JEFFERYS
    fname:         WILLIAM
    title:         DR.
    mi:            H.
    inst:          UNIVERSITY OF TEXAS AT AUSTIN
    country:       USA
general_form_text:
  question:        3
    section:       1
    line_1:   a) Observations will be made with the FGSs in POS mode. 1 obs-set
    line_2:     will consist of one observation of the minor planet followed by
    line_3:     4 ref stars, a repeat of the mp, a repeat of the 4 ref stars in
    line_4:     reverse order, and a final repeat of the mp.  (3min/mpobs,1min/ref-star)
    line_5:     Two of the reference stars are located at each end of the pickle,
    line_6:     to insure against losing the calibration if one of the ref
    line_7:     stars is double and cannot be locked in fine lock.  The repeated
    line_8:     observations are required to solve for he apparent rotation of the
    line_9:    astrometer FGS during the obs set.  We hve been successful solving
    line_10:   for this apparent rotation using the symmetric ref star procedure
    line_11:    with previous FGS measurements of Hipparcos star/QSO fields.
    line_12:    The amplitude of the motion can be as high as 10 milliarcseconds
    line_13:    during an observation set, while the solution yields
    line_14:    submilliarcsecond consistancy in many cases.
    line_15:        The observation set will be repeated for a total of 5 times
    line_16:    as the minor planet moves across the FGSFOV (pickle).  Ideally,
    line_17:    one observation set at each end of the pickle would suffice.
    line_18:    However, because of scheduling constraints and in order to
    line_19:    provide redundancy and possibly higher accuracy, five sets
    line_20:    across the pickle is the minimum acceptable.  If one observation
    line_21:    set at the end of the pickle is lost for whatever reason, we
    line_22:    would still have enough information to recover an acceptable
    line_23:    scale determination.
  question:        4
    section:       1
    line_1:     This measurement is necessary for the accurate calibration
    line_2:     of the FGS Astrometer Plate Scale at the milliarcsecond
    line_3:     level of accuracy over the length of the FGSFOV (18.6
    line_4:     arcminutes).  The next-best calibration is using FGS
    line_5:     observations of Hipparcos stars, and should be a factor of
    line_6:     4 - 5 worse than this method.
    line_7:        This calibration is necessary for HST Solar System
    line_8:        Astrometry with the FGS Astrometer, and for the calibration
    line_9:     of FGS measurements with respect to Extragalactic Objects
    line_10:     already made and continuing.
    line_11:   The most accurate value of the plate scale would come from
    line_12:   measuring the position of the minor planet continuously as
    line_13:   as it traverses the FGSFOV (Pickle).  Repeated measurements
    line_14:   of several reference stars are necessary to track the apparent
    line_15:   motion of the Pickle during the observation set.  The minimum
    line_16:   measurement would consist of two observation sets, one at each
    line_17:   end of the Pickle.  However, to be safe and allow for
    line_18:   observational and scheduling contingencies which would cancel
    line_19:   one or more observation sets as has happened in previous
    line_20:  apparitions of this proposal, we request five observation
    line_21:  sets spread across the Pickle which will yield an acceptable
    line_22:  calibration, even if one of the end obs sets does not get
    line_23:  (continued under question 5)....
  question:        5
    section:       1
    line_1:        This observation is time critical, based on asteroid size,
    line_2:        magnitude, speed and direction of motion through the pickle,
    line_3:        reference and guidestar availability, and many other factors.
    line_4:  QUESTION 4  continued:
    line_5:  get executed for some reason.  Each observation set will
    line_6:  take about 30 minutes i.e., one orbit.  The target will be
    line_7:  near opposition so that the observation will be made on the
    line_8:  on the dark side of the orbit.  Cycling through the minor
    line_9:  planet and the reference stars in the given order is necessary
    line_10:  to "track" the apparent motion of the Astrometer reference
    line_11:  frame on the sky.  Repeated observations of the minor planet
    line_12:  are necessary in case one is missed, and to give higher
    line_13:  accuracy and repeatability (error estimates) when more than
    line_14:  one setting is obtained in an observation set.
  question:        8
    section:       1
    line_1:        for further information contact Paul Hemenway,
    line_2:        University of Texas, Astronomy Department
    line_3:        paul@astro.as.utexas.edu
    line_4:        currently at University of St. Andrews, Scotland.
    line_5:        e-mail to the above address will be automatically
    line_6:        forwarded.
general_form_address:
  lname:           HEMENWAY
    fname:         PAUL
    mi:            D
    title:         DR.
    category:      CON
    inst:          UNIVERSITY OF TEXAS AT AUSTIN
    addr_1:        DEPARTMENT OF ASTRONOMY
    addr_2:        UNIVERSITY OF TEXAS AT AUSTIN
    city:          AUSTIN
    state:         TX
    zip:           78712
    country:       USA
    phone:         (512)471-3431
  lname:           JEFFERYS
    fname:         WILLIAM
    mi:            H.
    title:         DR.
    category:      PI
    inst:          UNIVERSITY OF TEXAS AT AUSTIN
    addr_1:        DEPARTMENT OF ASTRONOMY
    addr_2:        UNIVERSITY OF TEXAS AT AUSTIN
    city:          AUSTIN
    state:         TX
    zip:           78712
    country:       USA
    phone:         (512)471-1455
fixed_targets:
    targnum:       10
    name_1:        MP-POINTING
    descr_1:       J, 701
    pos_1:         RA = 18H 45M 44.177S +/- .008S,
    pos_2:         DEC = -20D 13' 35.030" +/- .008"
    equinox:       J2000
    targnum:       12
    name_1:        PAUL1
    descr_1:       J, 701
    pos_1:         RA = 281.50496D +/- 0.00001D,
    pos_2:         DEC = -20.43744D +/- 0.00001D
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       14
    name_1:        PAUL2
    descr_1:       J, 701
    pos_1:         RA 281.46472D +/- 0.00001D,
    pos_2:         DEC = -20.42449D +/- 0.00001D
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       16
    name_1:        PAUL3
    descr_1:       J, 701
    pos_1:         RA = 281.29662D +/- 0.00001D,
    pos_2:         DEC = -20.37026D +/- 0.00001D
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       18
    name_1:        PAUL4
    descr_1:       J, 701
    pos_1:         RA = 281.27234D +/- 0.00001D,
    pos_2:         DEC = -20.36241D +/- 0.00001D
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       19
    name_1:        PAUL5
    descr_1:       J, 701
    pos_1:         RA = 281.23121D +/- 0.00001D,
    pos_2:         DEC = -20.34910D +/- 0.00001D
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       20
    name_1:        MPREF1-REF
    descr_1:       J, 701
    pos_1:         RA = 18H 46M 01.169S +/- .008S,
    pos_2:         DEC = -20D 25' 37.740" +/- .008"
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.08
    targnum:       30
    name_1:        MPREF2-REF
    descr_1:       J, 701
    pos_1:         RA = 18H 45M 54.384S +/- .008S,
    pos_2:         DEC = -20D 26' 22.200" +/- .008"
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.28
    targnum:       40
    name_1:        MPREF3-REF
    descr_1:       J, 701
    pos_1:         RA = 18H 45M 07.692S +/- .008S,
    pos_2:         DEC = -20D 23' 46.788" +/- .008"
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.10
    targnum:       50
    name_1:        MPREF4-REF
    descr_1:       J, 701
    pos_1:         RA = 18H 45M 02.796S +/- .008S,
    pos_2:         DEC = -20D 21' 50.400" +/- .008"
    equinox:       J2000
    fluxnum_1:     1
    fluxval_1:     V = 13.49
solar_system_targets:
  targnum:         60
    name_1:        MP1626
    descr_1:       ASTEROID 1626
    lev1_1:        TYPE=ASTEROID,
    lev1_2:        A=2.3631911, E=0.2750806,
    lev1_3:        I=25.31048, O=279.05397,
    lev1_4:        W=148.78383, M=286.60422,
    lev1_5:        EPOCH=24-MAY-91:00:00:00,
    lev1_6:        EQUINOX=B1950
exposure_logsheet:
    linenum:       100.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MP-POINTING
    config:        S/C
    opmode:        POINTING
    aperture:      V1
    num_exp:       0
    time_per_exp:  0.0S
    req_1:         SEQ 100-111 NO GAP;
    req_2:         SAME POS FOR 101-111 AS 100
    linenum:       101.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      #
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  3M
    param_1:       FES-TIME=0.025,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       102.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF1-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       103.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF2-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       104.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF3-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       105.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF4-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       106.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      #
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  3M
    param_1:       FES-TIME=0.025,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       107.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF4-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       108.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF3-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       109.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF2-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       110.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      MPREF1-REF
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  51.2S
    param_1:       FES-TIME=DEF,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       111.000
    sequence_1:    DEFINE
    sequence_2:    MP-OBS1
    targname:      #
    config:        FGS
    opmode:        POS
    aperture:      3
    sp_element:    F583W
    num_exp:       1
    time_per_exp:  3M
    param_1:       FES-TIME=0.025,
    param_2:       NULL = YES,
    param_3:       LOCK = FINE,
    param_4:       DATA-RATE=32,
    param_5:       ACQ-MODE = SEARCH,
    param_6:       ACQ-DIST = 15
    linenum:       200.000
    sequence_1:    USE
    sequence_2:    MP-OBS1
    targname:      PAUL1
    req_1:         AT 9-JUL-94:21:40 +/- 2.67H;
    req_2:         ORIENT 109.5D +/- 0.01D;
    req_3:         CYCLE 4
    comment_1:     IT IS ABSOLUTELY IMPERATIVE 
    comment_2:     TO KEEP THE SAME POINTING 
    comment_3:     AND ORIENT FOR ALL OBSERVATIONS
    linenum:       300.000
    sequence_1:    USE
    sequence_2:    MP-OBS1
    targname:      PAUL2
    req_1:         AT JD2449543.526 +/- .111D;
    req_2:         ORIENT 109.5D +/- 0.01D;
    req_3:         CYCLE 4 / 300-600
    comment_1:     IT IS ABSOLUTELY IMPERATIVE 
    comment_2:     TO KEEP THE SAME POINTING 
    comment_3:     AND ORIENT FOR ALL OBSERVATIONS
    linenum:       400.000
    sequence_1:    USE
    sequence_2:    MP-OBS1
    targname:      PAUL3
    req_1:         AT JD2449543.85 +/- .111D;
    req_2:         ORIENT 109.5D +/- 0.01D;
    comment_1:     IT IS ABSOLUTELY IMPERATIVE 
    comment_2:     THAT WE KEEP THE SAME POINTING 
    comment_3:     AND ORIENT FOR ALL OBSERVATIONS
    linenum:       500.000
    sequence_1:    USE
    sequence_2:    MP-OBS1
    targname:      PAUL4
    req_1:         AT JD2449543.972 +/- .111D;
    req_2:         ORIENT 109.5D +/- 0.01D;
    comment_1:     IT IS ABSOLUTELY IMPERATIVE 
    comment_2:     TO KEEP THE SAME POINTING 
    comment_3:     AND ORIENT FOR ALL OBSERVATIONS
    linenum:       600.000
    sequence_1:    USE
    sequence_2:    MP-OBS1
    targname:      PAUL5
    req_1:         AT JD2449544.154 +/- .060D;
    req_2:         ORIENT 109.5D +/- 0.01D;
    comment_1:     IT IS ABSOLUTELY IMPERATIVE 
    comment_2:     TO KEEP THE SAME POINTING 
    comment_3:     AND ORIENT FOR ALL OBSERVATIONS
!~~~RPSS~~~,HEMENWAY,mpscale1626.prop, 1-MAR-1994 09:01