Physical Sciences and Mathematics Commons^™

Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey

Electronic Theses and Dissertations

Exoplanets represent a young, rapidly advancing subfield of astrophysics where much is still unknown. It is therefore important to analyze trends among their parameters to learn more about these systems. More complexity is added to these systems with the presence of additional stellar companions. To study these complex systems, one can employ programming languages such as Python to parse databases such as those constructed by TESS and Gaia to bridge the gap between exoplanets and stellar companions. Data can then be analyzed for trends in these multi-star exoplanet systems and in juxtaposition to their single-star counterparts. This research was able …

A Spectropolarimetric Study Of Southern Wr + O Binaries, Andrew G. Fullard

Electronic Theses and Dissertations

The classical Wolf-Rayet (WR) state is the evolved stage of a massive star, post main-sequence. They are characterized by their strong emission line spectra and stellar winds that are often more than 10 times denser than that of their progenitor O-type stars, which have mass loss rates of 10^-6 M_Θyr^-1. The evolution of WR stars and their connection to specific types of supernovae (SNe) is an open question. Current theory suggests that rapidly rotating massive stars may be the progenitors of SNe that produce long-duration gamma-ray bursts. The interaction between WR stars and their companion …

A Photometric Study Of The Eclipsing Binary V574 Lyrae, Abigail L.J. Rickards

Electronic Theses and Dissertations

Variable stars provide unparalleled insight into stellar evolution and eclipsing binary variables are particularly excellent laboratories for determining stellar physical parameters and behavior. These parameters, when taken with those of other stars, can be used to evaluate current theories on stellar evolution and stellar structure. With the view of contributing useful data to this cause, a photometric study of the eclipsing binary system V574 Lyrae (Lyr) was undertaken to determine the system's physical parameters and to create a model of the system. Data were collected with a 0.36 m Ritchey-Chr'etien telescope and the Sloan g', r', and i' filters and …

Polarized Bow Shock Nebulae Reveal Features Of The Winds And Environments Of Massive Stars, Manisha Shrestha

Electronic Theses and Dissertations

Massive stars strongly affect their surroundings through their energetic stellar winds during their lifetime and through their energetic deaths as supernovae. When a stellar wind interacts with the local interstellar medium (ISM), if the relative velocity between wind and ISM is supersonic, then a stellar wind bow shock is formed. Bow shocks and related density enhancements produced by the winds of massive stars moving through the interstellar medium provide important information regarding the motions of the stars, the properties of their stellar winds, and the characteristics of the local medium. Since bow shock nebulae are aspherical structures, light scattering within …

Celestial Paleontology: The Legacy Of Dying Stars, Alexa Hodgson Hart

Electronic Theses and Dissertations

In their death throes, stars dole out their atmospheric material to the interstellar medium in dramatic stellar winds and spectacular explosions. The details of this profound metamorphosis, from star to remnant, play a key role in the next generation of star formation as well as the energetic and chemical evolution of galaxies and the universe as a whole. Dying stars are thought to be the source of all of the nuclei heavier than iron in the universe, as well as more complex molecules, such as carbon chains, which form the backbone of life as we know it.

High mass Wolf-Rayet …