Description
As the detection of planets become commonplace around our neighboring stars, scientists can now begin exploring their possible properties and habitability. Using statistical analysis I determine a true range of elemental compositions amongst local stars and how this variation could affect possible planetary systems. Through calculating and analyzing the variation in elemental abundances of nearby stars, the actual range in stellar abundances can be determined using statistical methods. This research emphasizes the diversity of stellar elemental abundances and how that could affect the environment from which planets form. An intrinsic variation has been found to exist for almost all of the elements studied by most abundance-finding groups. Specifically, this research determines abundances for a set of 458 F, G, and K stars from spectroscopic planet hunting surveys for 27 elements, including: C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, La, Ce, Nd, Eu, and Hf. Abundances of the elements in many known exosolar planet host stars are calculated for the purpose investigating new ways to visualize how stellar abundances could affect planetary systems, planetary formation, and mineralogy. I explore the Mg/Si and C/O ratios as well as place these abundances on ternary diagrams with Fe. Lastly, I emphasize the unusual stellar abundance of τ Ceti. τ Ceti is measured to have 5 planets of Super-Earth masses orbiting in near habitable zone distances. Spectroscopic analysis finds that the Mg/Si ratio is extremely high (~2) for this star, which could lead to alterations in planetary properties. τ Ceti's low metallicity and oxygen abundance account for a change in the location of the traditional habitable zone, which helps clarify a new definition of habitable planets.
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Details
Title
- Variability of elemental abundances in the local neighborhood and its effect on planetary systems
Contributors
- Pagano, Michael (Author)
- Young, Patrick (Thesis advisor)
- Shim, Sang-Heon (Committee member)
- Patience, Jennifer (Committee member)
- Desch, Steven (Committee member)
- Anbar, Ariel (Committee member)
- Arizona State University (Publisher)
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2014
Subjects
Resource Type
Collections this item is in
Note
- thesisPartial requirement for: Ph.D., Arizona State University, 2014
- bibliographyIncludes bibliographical references (p. 94-101)
- Field of study: Astrophysics
Citation and reuse
Statement of Responsibility
by Michael Pagano