10555(  6) - 07/05/05 13:27  - [  1]

                  HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10555

Version: 6    Check-in Time: 05-Jul-2005 17:26:51

Title
A Search for Satellites Around Kuiper Belt Objects Which Exhibit High Angular
Momentum
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Type             Cycle     Parallel Pointing Tolerance
GO               14        <none>
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Investigators
                                                                                     Contact?
    PI: Dr. Scott S. Sheppard             Carnegie Institution of Washington
   CoI: Dr. Keith S. Noll                 Space Telescope Science Institute             N

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Abstract

We propose to use the HST to search for satellites around Kuiper Belt Objects which
have large amplitude, fast rotational light curves. Large main belt asteroids with
similar light curve characteristics have been found to have near an 80 percent
companion rate. This is over an order of magnitude more than the companion rate of
main belt asteroids in general. The satellites were probably formed during the
process which imparted the high angular momentum on the primary object. To date five
Kuiper Belt objects exhibit high angular momentum through their rotational light
curves. Two of them have been observed with STIS on the HST and one was found to be
a binary. We request three orbits with HST/ACS in order to obtain deep high
resolution images of the other three Kuiper Belt objects that have large amplitudes
and fast rotations. In addition, we request one orbit to reobserve the other KBO
which didn't have a satellite detection in order to obtain deeper and better
resolution images than the first observations. Finding binaries is important not
only to understand the processes which created the high angular momentum of the
primary but also in determining the bulk densities and collisional histories of the
objects.
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                                                10555(  6) - 07/05/05 13:27  - [  2]

  Observations Description
  ------------------------

     Our targets are KBOs which have high angular momenta and have similar sizes as
     the main belt asteroids of comparable characteristics. We also need to observe
     similar sized satellites in the Kuiper belt as those found around the main belt
     asteroids. The main belt asteroids satellites are around 10 to 15 km in
     diameter. We need to reach a magnitude of about 28 to be able to detect a KBO
     this size in the Kuiper belt assuming a low to moderate albedo. ACS/HRC can
     reach a signal to noise of about 5 with optimal PSF fitting at 28th magnitude
     in about 2400 seconds. As mentioned at the end of the Science Justification we
     request time to observe 4 KBOs to search for companions. Three of the KBOs have
     not been observed by HST while KBO 2000 GN171 was observed once before with
     HST/STIS to about 27th magnitude. The targets in our sample have V-band
     magnitudes between $20<$V$<23$. PSF fitting will be used to search for
     satellites of each KBO observed. Each KBO will need to be imaged several times
     during one visit with dithers between exposures to take out cosmic rays and
     chip defects. The KBOs are non-sidereally moving objects which have maximum
     motions of about 4 arcseconds per hour as seen from the Earth at opposition.
     They are near the ecliptic plane. Slight zodiacal light and Earth shine should
     not be a problem. We will use the Broad V F606W filter for observations.
     Standard guide star acquisition will take 6 minutes for an object. The ACS/HRC
     overhead is 2.5 minutes for the first exposure and 1 minute for each additional
     exposure. We require dithering between exposures and this will add an
     additional 30 seconds per exposure. We will use tracking to move at the
     nonsidereal rates of the object while imaging. Four 600 second images will be
     taken of each KBO in order to remove noise from cosmic rays and chip defects.
     With overheads this is 6 min+ 2.5 min + (3 x 1 min) + (3 x 0.5 min) + (4 x 10
     min) = 53 minutes per object. Since each of our objects will be visible for
     about 55 minutes per orbit we require one orbit per object to reach the
     sensitivity we desire. Thus we request 4 orbits with HST/ACS/HRC.

  Real Time Justification
  -----------------------


  Calibration Justification
  -------------------------


  Additional Comments
  -------------------

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                                                10555(  6) - 07/05/05 13:27  - [  3]

TARGET LIST    Solar System Targets
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    1    |    TARGET NAME: 32929
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TARGET DESCRIPTION: ASTEROID asteroid 32929
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           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    TYPE=ASTEROID,A=39.4641155,E=0.2599466,I                  |
    =4.84603,O=342.11102,W=25.21573,M=358.02                  |
    996,EPOCH=30-Jan-2005,EQUINOX=J2000                       |
                                                              |
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    A_VEL 32929 FROM HUBBLE GT 0.0000417
                                                              |
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DATA                                                          |            COMMENTS
                                                              |
V = 21.8+/-0.5                                                |    We want to observe the Kuiper Belt
                                                              |    Object when its parallax motion
                                                              |    allows it to at least move 3 pixels
                                                              |    during one orbit (or 2400 seconds).
                                                              |    This will allow us to determine
                                                              |    which object is the Kuiper Belt
                                                              |    object and any possible satellites
                                                              |    versus what are stationary
                                                              |    background objects. We attempt to
                                                              |    put this constraint in below using
                                                              |    the "Observing Windows" section
                                                              |    limiting the minimum angular
                                                              |    velocity. Also, if this severly
                                                              |    limits when we can make our
                                                              |    observations than this angular
                                                              |    velocity limit can be removed.
                                                              |
Ephemeris Uncertainty:   0.1 S                                |
Acquisition Uncertainty: 1.0 "                                |

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                                                10555(  6) - 07/05/05 13:27  - [  4]

TARGET LIST    Solar System Targets
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    2    |    TARGET NAME: 20000
------------------------------------------------------------------------------------------------------------------------------------
TARGET DESCRIPTION: ASTEROID asteroid 20000
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    TYPE=ASTEROID,A=43.0698299,E=0.0511015,I                  |
    =17.16869,O=97.3006,W=270.17391,M=91.849                  |
    85,EPOCH=30-Jan-2005,EQUINOX=J2000                        |
                                                              |
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    A_VEL 20000 FROM HUBBLE GT 0.0000417
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
DATA                                                          |            COMMENTS
                                                              |
V = 20.0+/-0.5                                                |    We want to observe the Kuiper Belt
                                                              |    Object when its parallax motion
                                                              |    allows it to at least move 3 pixels
                                                              |    during one orbit (or 2400 seconds).
                                                              |    This will allow us to determine
                                                              |    which object is the Kuiper Belt
                                                              |    object and any possible satellites
                                                              |    versus what are stationary
                                                              |    background objects. We attempt to
                                                              |    put this constraint in below using
                                                              |    the "Observing Windows" section
                                                              |    limiting the minimum angular
                                                              |    velocity. Also, if this severly
                                                              |    limits our viewing or observing
                                                              |    chances than this angular velocity
                                                              |    limit may be removed.
                                                              |
Ephemeris Uncertainty:   0.1 S                                |
Acquisition Uncertainty: 1.0 "                                |

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                                                10555(  6) - 07/05/05 13:27  - [  5]

TARGET LIST    Solar System Targets
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    3    |    TARGET NAME: 2001QG298
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TARGET DESCRIPTION: ASTEROID asteroid 2001QG298
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           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    TYPE=ASTEROID,A=39.1843938,E=0.1915167,I                  |
    =6.50351,O=162.57295,W=211.50766,M=349.8                  |
    8454,EPOCH=30-Jan-2005,EQUINOX=J2000                      |
                                                              |
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    A_VEL 2001QG298 FROM HUBBLE GT 0.0000417
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
DATA                                                          |            COMMENTS
                                                              |
V = 22.5+/-0.5                                                |    We want to observe the Kuiper Belt
                                                              |    Object when its parallax motion
                                                              |    allows it to at least move 3 pixels
                                                              |    during one orbit (or 2400 seconds).
                                                              |    This will allow us to determine
                                                              |    which object is the Kuiper Belt
                                                              |    object and any possible satellites
                                                              |    versus what are stationary
                                                              |    background objects. We attempt to
                                                              |    put this constraint in below using
                                                              |    the "Observing Windows" section
                                                              |    limiting the minimum angular
                                                              |    velocity. Also, if this severly
                                                              |    limits our viewing or observing
                                                              |    chances than this angular velocity
                                                              |    limit may be removed.
                                                              |
Ephemeris Uncertainty:   0.1 S                                |
Acquisition Uncertainty: 1.0 "                                |

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                                                10555(  6) - 07/05/05 13:27  - [  6]

TARGET LIST    Solar System Targets
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    4    |    TARGET NAME: 47932
------------------------------------------------------------------------------------------------------------------------------------
TARGET DESCRIPTION: ASTEROID asteroid 47932
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    TYPE=ASTEROID,A=39.6896218,E=0.2869864,I                  |
    =10.79551,O=26.09245,W=194.65842,M=353.1                  |
    1502,EPOCH=30-Jan-2005,EQUINOX=J2000                      |
                                                              |
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    A_VEL 47932 FROM HUBBLE GT 0.0000417
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
DATA                                                          |            COMMENTS
                                                              |
V = 20.9+/-0.5                                                |    We want to observe the Kuiper Belt
                                                              |    Object when its parallax motion
                                                              |    allows it to at least move 3 pixels
                                                              |    during one orbit (or 2400 seconds).
                                                              |    This will allow us to determine
                                                              |    which object is the Kuiper Belt
                                                              |    object and any possible satellites
                                                              |    versus what are stationary
                                                              |    background objects. We attempt to
                                                              |    put this constraint in below using
                                                              |    the "Observing Windows" section
                                                              |    limiting the minimum angular
                                                              |    velocity. Also, if this severly
                                                              |    limits our viewing or observing
                                                              |    chances than this angular velocity
                                                              |    limit may be removed.
                                                              |
Ephemeris Uncertainty:   0.1 S                                |
Acquisition Uncertainty: 1.0 "                                |

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                                                10555(  6) - 07/05/05 13:27  - [  7]

Patterns
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Pattern_Number: 1

                    Primary_Pattern                   Secondary_Pattern
Pattern_Type        ACS-HRC-DITHER-BOX
Pattern_Purpose     DITHER
Number_Of_Points    4
Point_Spacing       0.2
Line_Spacing        0.098
Coordinate_Frame    POS-TARG
Pattern_Orient      19.89
Angle_Between_Sides 63.5
Center_Pattern      NO

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                                                10555(  6) - 07/05/05 13:27  - [  8]

Visit: 01
     Visit Priority:      <none>
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
------------------------------------------------------------------------------------------------------------------------------------
Exp |   Target  | Instr  | Oper. | Aper    |Spectral|Central|           Optional           |Num|   Time   |       Special
Num |    Name   | Config | Mode  | or FOV  |Element |Waveln.|          Parameters          |Exp|          |     Requirements
------------------------------------------------------------------------------------------------------------------------------------
1    20000       ACS/HRC  ACCUM   HRC       F606W            CR-SPLIT=NO                    1   620 S      PATTERN 1 1
   Comments:  We want four images per object for one orbit
              (to remove cosmic rays and bad pixels). Right
              now we put 620 seconds per image, but this
              integration per image may be reduced by up to
              10% if needed to fit a smaller observation
              window.
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Sub Exposures
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Target             | Exp |Instr   | Oper. |  Aper  |Spectral|Cent.|Primary     |Secondary   |Iteration |CR-SPLIT  |Orbit  |Duration
Name               | Num |Config  | Mode  | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num       |Num       |Number |
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20000               1     ACS/HRC  ACCUM   HRC      F606W          1            none         none       none       1       N/A
20000               1     ACS/HRC  ACCUM   HRC      F606W          2            none         none       none       1       N/A
20000               1     ACS/HRC  ACCUM   HRC      F606W          3            none         none       none       1       N/A
20000               1     ACS/HRC  ACCUM   HRC      F606W          4            none         none       none       1       N/A
                                                10555(  6) - 07/05/05 13:27  - [  9]

Visit: 02
     Visit Priority:      <none>
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
------------------------------------------------------------------------------------------------------------------------------------
Exp |   Target  | Instr  | Oper. | Aper    |Spectral|Central|           Optional           |Num|   Time   |       Special
Num |    Name   | Config | Mode  | or FOV  |Element |Waveln.|          Parameters          |Exp|          |     Requirements
------------------------------------------------------------------------------------------------------------------------------------
1    32929       ACS/HRC  ACCUM   HRC       F606W            CR-SPLIT=NO                    1   620 S      PATTERN 1 1
   Comments:  We want four images per object for one orbit
              (to remove cosmic rays and bad pixels). Right
              now we put 620 seconds per image, but this
              integration per image may be reduced by up to
              10% if needed to fit a smaller observation
              window.
------------------------------------------------------------------------------------------------------------------------------------

Sub Exposures
------------------------------------------------------------------------------------------------------------------------------------
Target             | Exp |Instr   | Oper. |  Aper  |Spectral|Cent.|Primary     |Secondary   |Iteration |CR-SPLIT  |Orbit  |Duration
Name               | Num |Config  | Mode  | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num       |Num       |Number |
------------------------------------------------------------------------------------------------------------------------------------
32929               1     ACS/HRC  ACCUM   HRC      F606W          1            none         none       none       1       N/A
32929               1     ACS/HRC  ACCUM   HRC      F606W          2            none         none       none       1       N/A
32929               1     ACS/HRC  ACCUM   HRC      F606W          3            none         none       none       1       N/A
32929               1     ACS/HRC  ACCUM   HRC      F606W          4            none         none       none       1       N/A
                                                10555(  6) - 07/05/05 13:27  - [ 10]

Visit: 03
     Visit Priority:      <none>
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
------------------------------------------------------------------------------------------------------------------------------------
Exp |   Target  | Instr  | Oper. | Aper    |Spectral|Central|           Optional           |Num|   Time   |       Special
Num |    Name   | Config | Mode  | or FOV  |Element |Waveln.|          Parameters          |Exp|          |     Requirements
------------------------------------------------------------------------------------------------------------------------------------
1    2001QG298   ACS/HRC  ACCUM   HRC       F606W            CR-SPLIT=NO                    1   620 S      PATTERN 1 1
   Comments:  We want four images per object for one orbit
              (to remove cosmic rays and bad pixels). Right
              now we put 620 seconds per image, but this
              integration per image may be reduced by up to
              10% if needed to fit a smaller observation
              window.
------------------------------------------------------------------------------------------------------------------------------------

Sub Exposures
------------------------------------------------------------------------------------------------------------------------------------
Target             | Exp |Instr   | Oper. |  Aper  |Spectral|Cent.|Primary     |Secondary   |Iteration |CR-SPLIT  |Orbit  |Duration
Name               | Num |Config  | Mode  | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num       |Num       |Number |
------------------------------------------------------------------------------------------------------------------------------------
2001QG298           1     ACS/HRC  ACCUM   HRC      F606W          1            none         none       none       1       N/A
2001QG298           1     ACS/HRC  ACCUM   HRC      F606W          2            none         none       none       1       N/A
2001QG298           1     ACS/HRC  ACCUM   HRC      F606W          3            none         none       none       1       N/A
2001QG298           1     ACS/HRC  ACCUM   HRC      F606W          4            none         none       none       1       N/A
                                                10555(  6) - 07/05/05 13:27  - [ 11]

Visit: 04
     Visit Priority:      <none>
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
------------------------------------------------------------------------------------------------------------------------------------
Exp |   Target  | Instr  | Oper. | Aper    |Spectral|Central|           Optional           |Num|   Time   |       Special
Num |    Name   | Config | Mode  | or FOV  |Element |Waveln.|          Parameters          |Exp|          |     Requirements
------------------------------------------------------------------------------------------------------------------------------------
1    47932       ACS/HRC  ACCUM   HRC       F606W            CR-SPLIT=NO                    1   620 S      PATTERN 1 1
   Comments:  We want four images per object for one orbit
              (to remove cosmic rays and bad pixels). Right
              now we put 620 seconds per image, but this
              integration per image may be reduced by up to
              10% if needed to fit a smaller observation
              window.
------------------------------------------------------------------------------------------------------------------------------------

Sub Exposures
------------------------------------------------------------------------------------------------------------------------------------
Target             | Exp |Instr   | Oper. |  Aper  |Spectral|Cent.|Primary     |Secondary   |Iteration |CR-SPLIT  |Orbit  |Duration
Name               | Num |Config  | Mode  | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num       |Num       |Number |
------------------------------------------------------------------------------------------------------------------------------------
47932               1     ACS/HRC  ACCUM   HRC      F606W          1            none         none       none       1       N/A
47932               1     ACS/HRC  ACCUM   HRC      F606W          2            none         none       none       1       N/A
47932               1     ACS/HRC  ACCUM   HRC      F606W          3            none         none       none       1       N/A
47932               1     ACS/HRC  ACCUM   HRC      F606W          4            none         none       none       1       N/A
                                                10555(  6) - 07/05/05 13:27  - [ 12]

            Summary Form for Proposal  10555

  Item                         Used in this proposal
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  Apertures                    HRC
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  Configurations               ACS/HRC
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  Opmodes                      ACCUM
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  Optional Parameters          CR-SPLIT=NO
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  Proposal Category            GO
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  Special Requirements         PATTERN 1 1
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  Spectral Elements            F606W
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  Target Names                 20000 32929 2001QG298 47932
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