7992(  1) - 04/16/98 14:10  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7992
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:07:47

1.Proposal Title:
Searching for Brown Dwarfs and Extreme M Dwarfs in STIS Parallel Observations
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2. Proposal For  3. Cycle
AR               7
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4. Investigators
                                                                                     Contact?
    PI: Dr. Philip Plait                  Advanced Computer Concepts, Inc.
   CoI: Dr. Donna Weistrop                University of Nevada, Las Vegas               N
   CoI: Jennifer Sandoval                 Advanced Computer Concepts, Inc.              N

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5. Abstract

We propose to use STIS parallel images and spectra to search for extremely late M
dwarfs and brown dwarfs. Data already available show that many STIS parallel fields
contain candidate stars and that spectral classification of these stars is possible.
We estimate that there will be 50 late dwarfs detected in the parallels by the end
of the grant period. We have performed preliminary analysis on one field
specifically and found many candidates stars, two of which are at least as late as
type M7 and one that may be as late as M10. Identification of spectral features is
crucial to this study to distinguish M dwarfs, giants, brown dwarfs, and reddened
hot stars, but is severely compromised by detector fringing which makes intrinsic
spectral features very difficult or impossible to uniquely identify. Flat fielding
the parallel spectra using pipeline processing will not remove the fringing, and
indeed will actually worsen the situation. However, we have made a recent advance in
reduction software that greatly reduces the effects of fringing, making it possible
to identify the intrinsic stellar spectral features. Absolute photometry can be also
performed to better than 1\ to find their distance. This has important implications
for the low-mass end of the luminosity function in the solar neighborhood, which is
still not well understood.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
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                                                7992(  1) - 04/16/98 14:10  - [  2]

            Summary Form for Proposal  7992

  Item                         Used in this proposal
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  Proposal Category            AR
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