7539(  1) - 12/14/96 00:48  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7539
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:19:36

1.Proposal Title:
Extragalactic Open Clusters: A Catalog of Clusters in M31 and M33
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2. Scientific Category   3. Proposal For  4. Cycle
STELLAR POPULATIONS         AR               7
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5. Investigators
                                                                                     Contact?
    PI: Patrick Seitzer                   University of Michigan
   CoI: Maritza Tavarez                   University of Michigan                        N
   CoI: Eileen Friel                      Boston University                             N
   CoI: Kenneth Janes                     Boston University                             N

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6. Abstract

Star clusters are ideal tracers of the past star formation history of a disk of a
spiral galaxy after HII regions and OB associations have faded from view. We propose
to use archival WFPC2 VRI observations of the spiral galaxies M31 and M33 to
assemble a catalog of open clusters in these two galaxies. Existing groundbased
catalogs are seriously incomplete due to the small scale lengths (less than 1") of
the clusters. HST resolves the open clusters in both of these galaxies, so
distinguishing stars from clusters is not a problem. The HST catalog will produce a
catalog of cluster location, magnitude, and scale length. With followup ground based
observations of the clusters, we can start to address questions such as: what is the
specific frequency of open clusters in these two spiral galaxies? How do the cluster
sizes and luminosities, and their formation and destruction rates, depend on
environment? Do most stars in the disks of spirals form in, or in close association
with, clusters?
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:                                                              ,
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                                                7539(  1) - 12/14/96 00:48  - [  1]

            Summary Form for Proposal  7539

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          STELLAR POPULATIONS
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