8370(  2) - 12/18/98 16:50  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8370
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:48:59

1.Proposal Title:
Duplicity and Variability in HST Guide Stars - An FGS Serendipitous Survey
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: Glenn Schneider                   University of Arizona
   CoI: Dr. John Hershey                  Computer Sciences Corporation                 N
   CoI: Dr. Ed Nelan                      Space Telescope Science Institute             N

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5. Abstract

With the successful completion of AR/5811 we have demonstrated the efficacy of
extracting fundamental astrometric properties of stellar systems from HST guiding
data. The HST Fine Guidance Sensors (FGS) are capable of revealing duplicity in
faint, close binary systems and measuring their position angles and component
separations with a precision which far exceeds that which is possible using other
techniques. Intensity data which are produced by the FGS PMTs while in fine lock
provide high precision relative photometry on rapid time scales. As proposed in
AR/5811 we have built a data reduction and analysis pipeline to exploit these
capabilities in a serendipitous fashion using HST guiding data. We have recently
publish a new duplicity catalog from a search of 4882 HST guide stars observed in
13, 979 acquisitions spanning 22 months giving separations, position angles, and
relative brightnesses of the individual stellar components. Our pipeline also
extracts FGS photometric data in a form which permits examining light curves and
power spectra for astroseismological surveys of these stars, while looking for and
characterizing variations due to other intrinsic mechanisms. We now propose to take
full advantage of the ground-work which has been established by our pilot program by
continuing this survey for the large number of guide stars still to be examined, and
which will be observed in Cycle 8.
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  Data Distribution

  Paper Products:  NO
  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                8370(  2) - 12/18/98 16:50  - [  2]

            Summary Form for Proposal  8370

  Item                         Used in this proposal
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  Proposal Category            AR
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