8372(  2) - 12/18/98 16:51  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8372
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:49:44

1.Proposal Title:
Massive emission-line stars in nearby galaxies
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: Rene Walterbos                    New Mexico State University
   CoI: Dr. Mark Bransford                New Mexico State University                   N
   CoI: Ms. Nichole King                  New Mexico State University                   N

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5. Abstract

The HST archive contains numerous exposures in HAlpha and continuum light of nearby
(< 10 Mpc) galaxies. We propose to analyze these archival images to create a
database of massive stars with high mass-loss rates for galaxies of different Hubble
types. The catalog is expected to include candidate Luminous Blue Variables (cLBV),
Be stars and possibly some Wolf-Rayet stars. The HST data are unique for several
reasons: 1) the high spatial resolution and inclusion of continuum exposures allows
us to extend successful ground-based searches for stars with high mass loss rates in
the MCs, M31 and M33 out to ten times larger distances. Their HAlpha luminosities
and continuum emission provide estimates of the mass loss rates; 2) for galaxies out
to a few Mpc, the high resolution allows a search for resolved nebulae possibly
indicating eruptive mass loss; such nebulae are known to exist around LBVs in the
Galaxy and the LMC; and 3) data are available for different galaxy types with a
range of metallicities which will ultimately help in testing the ``Conti scenario''
for massive stellar evolution. The number of cLBVs and other extreme mass-loss stars
we expect to find, ranges from a few in the closest galaxies to as much as 50 in
M101. Finding these objects is an important first step in shedding light on the
poorly understood post-main sequence evolution of massive stars.
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  Data Distribution

  Paper Products:  NO
  Media:           ELECTRONIC
  Blocking Factor: 10
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                                                8372(  2) - 12/18/98 16:51  - [  2]

            Summary Form for Proposal  8372

  Item                         Used in this proposal
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  Proposal Category            AR
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