7993(  1) - 04/16/98 14:10  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7993
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:08:13

1.Proposal Title:
Accurate Internal Proper Motions in the Globular Cluster 47 Tucanae
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2. Proposal For  3. Cycle
AR               7
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4. Investigators
                                                                                     Contact?
    PI: Ivan King                         University of California
   CoI: Jay Anderson                      University of California                      N
   CoI: Georges Meylan                    European Southern Observatory                 N

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5. Abstract

We will measure internal proper motions of stars in 47 Tuc to an unprecedentedly
high accuracy---error per star about 1/5 of the internal velocity dispersion in the
cluster. In addition to images already secured by Meylan in 1995 and 1997 (GO-5912,
6467), we will use archival images going back to 1991, which will greatly increase
the overall accuracy. We demonstrate herein our ability to measure accurate proper
motions from both WFPC-1 and WFPC2 material. The dispersion of proper motions, when
compared with the known dispersion in radial velocities, will yield a far more
accurate distance for the cluster than has been available until now.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                7993(  1) - 04/16/98 14:10  - [  2]

            Summary Form for Proposal  7993

  Item                         Used in this proposal
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  Proposal Category            AR
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