7998(  1) - 04/16/98 14:13  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7998
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:09:43

1.Proposal Title:
Calibrating the Boron Abundances in Solar -Type Stars
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2. Proposal For  3. Cycle
AR               7
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4. Investigators
                                                                                     Contact?
    PI: Verne V. Smith                    The University of Texas at El Paso
   CoI: Katia Cunha                       The University of Texas at El Paso            N

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5. Abstract

We will use the archive of GHRS moderate- and high-resolution spectra of F-G dwarf
and subgiant stars to improve our ability to synthesize and interpret the spectral
region containing the B I resonance doublet near 2497Angstrom\ . Our efforts in
synthesizing the solar spectrum, as a first step in the analysis of HST/GHRS data,
indicate that there is quite probably a missing source of continuous opacity in the
Sun and in stars similar to the Sun. This apparent source of continuous opacity
seems to vanish in the hotter F subgiant Procyon and we suspect a low-ionization
metal bound-free opacity (such as Mg I) as the missing source. In order to improve
the analysis, derivation, and interpretation of boron abundances obtained from this
spectral region, we propose to analyze all archived GHRS spectra of F and G dwarf
and subgiant stars in order to quantify the behavior of this possible opacity source
as a function of temperature and metallicity. By mapping the behavior of this
opacity source we can: 1) apply empirical corrections as necessary and 2) identify
the possible nature of such an opacity source. The results from this study will
enable us to critically evaluate and improve our ability to derive reliable
abundances of the key light element boron in solar-type stars.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                7998(  1) - 04/16/98 14:13  - [  2]

            Summary Form for Proposal  7998

  Item                         Used in this proposal
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  Proposal Category            AR
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