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   <!--Date: Thu Apr 06 21:29:32 GMT 2017-->
   
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   <ProposalInformation
      Category="AR"
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      <Title>Disintegrating Comet 73P</Title>
      
      <Abstract>Disintegration may be the leading cause of the demise of cometary nuclei yet is rarely observed and not well understood.  We propose to use an amazing but largely unpublished archival dataset on comet 73P/Schwassmann-Wachmann 3 from HST in order to characterize the breakup of this body, focussing on components 73-B, 73-C and 73-G from GO 8699, 10625 and 10992.  We will measure the number, sizes, velocities and (short-term) photometric variability of the fragments in 73-B and 73-G and derive the ejection speeds and times.  A nucleus/coma convolution model will be used to extract the best estimates of fragment and nucleus size.  The size distributions and integral masses will be compared to the parent body masses to estimate lifetimes.  Lightcurves will be determined to the test the possibility that disintegration is due to rotational instability.</Abstract>
      
      <PrincipalInvestigator
         Honorific="Dr."
         FirstName="David"
         LastName="Jewitt"
         ESAMember="false"
         CSAMember="false"
         Retired="false"
         UniqueID="4421"
         Institution="University of California - Los Angeles"
         Country="USA"
         State="CA"
         Contact="true" />
      
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         Honorific="Dr."
         FirstName="Jessica"
         LastName="Agarwal"
         ESAMember="true"
         CSAMember="false"
         Retired="false"
         UniqueID="9402"
         Institution="Max Planck Institute for Solar System Research"
         Country="DEU"
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      <CoInvestigator
         Honorific="Dr."
         FirstName="Jing"
         LastName="Li"
         ESAMember="false"
         CSAMember="false"
         Retired="false"
         UniqueID="16864"
         Institution="University of California - Los Angeles"
         Country="USA"
         State="CA"
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         Institution="Space Telescope Science Institute"
         Country="USA"
         State="MD"
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         AdminUSPI="false" />
      
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      <Phase1ProposalInformation
         Attachment="/Users/jewitt/Dropbox/HST_73P_Archive/73P_archive_4.pdf">
         
         <ScientificCategory>Solar System</ScientificCategory>
         
         <ScientificKeyword1
            Keyword="Comets" />
         
         <ScientificKeyword2
            Keyword="Kuiper-Belt Objects" />
         
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            Default="true">0</ProprietaryPeriod>
         
         <Budget>Regular</Budget>
         
         <CalibProp>false</CalibProp>
         
         <UvInit>false</UvInit>
         
         <Theory>false</Theory>
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