Photometric parallaxes and subdwarf identification for M-type stars

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dc.contributor.advisor Robertson, Thomas H. (Thomas Herbert) Thompson, Dayna L. 2012-08-02T17:33:56Z 2012-08-02T17:33:56Z 2012-07-21 2012-07-21
dc.description.abstract Photometric data on the Kron-Cousins photometric system have been obtained for 118 new late K to middle M-type stars with known distances. These data have been used to obtain absolute red magnitudes, to construct a color-magnitude diagram, and to compute a polynomial function for disk dwarf stars in the color range 1.5 ≤ R-I < 2.0, which can be used to compute absolute red magnitudes to be used for photometric parallaxes. Such photometric parallaxes allow new stellar distance estimations that are essential when modeling the spatial distribution of stars in our Galaxy. This is especially important for M-type stars, as they make up more than half of the mass of the Milky Way. Intermediate-band CaH observations have also been obtained in an ongoing effort to distinguish stellar luminosity classes and populations; R-L and R-I colors are used to identify possible subdwarf stars. A total of seven possible new subdwarfs and three previously known subdwarfs have been identified with this method.
dc.description.sponsorship Department of Physics and Astronomy
dc.subject.lcsh Parallax -- Stars.
dc.subject.lcsh Astronomical photometry.
dc.subject.lcsh M stars -- Magnitudes.
dc.subject.lcsh Red dwarf stars.
dc.title Photometric parallaxes and subdwarf identification for M-type stars en_US Thesis (M.S.)

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  • Master's Theses [5510]
    Master's theses submitted to the Graduate School by Ball State University master's degree candidates in partial fulfillment of degree requirements.

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