SPECTROSCOPIC ANALYSES OF NEUTRON CAPTURE ELEMENTS IN OPEN CLUSTERS by JULIA E. O'CONNELL Bachelor of Science, 2011 Tennessee State University Nashville, Tennessee Submitted to the Graduate Faculty of the College of Science and Engineering Texas Christian University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2017 ACKNOWLEDGEMENTS I had the pleasure of having lunch with Caty Pilachowski during an American Astro- nomical Society (AAS) meeting in Long Beach, California. During lunch, Caty asked me what I wanted to do with astronomy. She had a right to be curious. She was the reason I was there. I stumbled over all the obvious answers, \I want to teach; I wanted to do research; I'd like to find a way to share my research with the public." She sat quietly and smiled. After I had exhausted all of the obvious choices, that quiet smile persisted. Finally, I sighed and admitted, \I don't know, Caty. I just wanted to study astronomy." That smile turned into a grin as she said, \We all did, dear." I felt relieved, but somehow part of a larger community. I didn't quite understand that sense of a larger community then, but I'm quite certain she understood my inability to understand. The conversation casually turned to small-talk about some sights I might be interested in seeing while in Long Beach, beyond the convention. It was 2009, the International Year of Astronomy. When I found Caty at the meeting, I told her that I had just talked with someone who knew her. \Imagine," she said, as she turned to introduce me to Chris Sneden. As a graduate student, Chris had developed a tool for stellar spectroscopists that is still the model software for all stellar spectro- scopists, MOOG. Chris asked me what I thought \MOOG" stood for, adding that many had tried to guess what it meant as an acronym. I told him that, in my mind, \MOOG" was a stellar analog for a musical synthesizer. He smiled, and asked to see my work. Since that time, Chris Sneden and Caty Pilachowski have continued to support my work and have, always graciously, offered commentary and advise on analysis techniques, pub- lications and my continuing education. I am deeply grateful that they have been, and will continue to be, a central part of my larger professional community. In the beginning there was not light, only the realization that I had to earn a physics degree in order to study astronomy. That should have been enough to stop any right- thinking individual, but I told myself if I was terrible at the math I would do something else. As badly as I wanted it, sometimes wanting something just isn't enough| so much to learn, so much to re-learn. By sheer chance, Stefan Forcey became my Calculus pro- fessor. He made me a better physics student, instantly, when he told me that if two different equations equal the same thing, you can use them anywhere you want. I hadn't even finished my question. I can't say if he remembers the conversation, but it was a pivot point for me. Physics was suddenly doable. By design, Stefan became my calculus teacher for the next three years. As my astronomy educator, Geoff Burks would oscillate between dressing me down in a lecture hall of 70 for missing a class and finding a timely scholarship, REU program or mentor that would keep me funded, interested and working. At one point, so I would have a place to work, he moved a corner bookcase from his home into his tiny office in ii the Center of Excellence on Tennessee State University campus, and then made sure I had access to the office when he was busy elsewhere. Geoff taught me that I could never imagine the scale of the Universe, but that I could imagine my place in it. Then he made me look. Geoff expected, no, demanded more from me, even as he assured me that I couldn't know everything. Like any good astronomer, Geoff is always focused on the bigger picture. As an undergraduate, Matthew Muterspaugh always had something for me to do: Make a graphic for the light path of this interferometer; find the riddle in this article I'm submitting on Friday; make a model of the new guiding head we're installing on the 2 meter robotic telescope. \We're installing." He literally turned up his nose at a report I wrote in Word about the installation. Matthew made me re-write the report in latex typesetting, which I first had to learn. He sent me templates, and waited patiently. In the meantime, we talked. Each conversation a continuation of the last, a progression to- ward being a professional astronomer. Sometimes we talked about what the implications would be if this or that were confirmed or denied. When it came to the topic of life on other planets, he said, \The implications would be profound in either case." Matthew introduced me to the gears of science, but Caty introduced me to the sci- ence. The science of stellar spectroscopy. Geoff had suggested I email Caty to start a conversation, one that might lead to a summer REU with her. Of all things, I talked about rainbows. I had no way of knowing, but Caty loves rainbows. That's how it started, with what was possible, with what light could tell us. We published a paper 2 years later, and I presented preliminary results at the AAS meeting in Long Beach where we had lunch. I am still discovering the depths of her knowledge and dedication to her craft. I started practicing analysis techniques that Caty had introduced me to at the corner bookcase in Geoff's tiny office, while Matthew continued to find projects for me, and Ste- fan taught me the unspoken rules of physics. Their dedication is a tribute to educators everywhere, and my gratitude cannot be fully expressed here. Words can be such paltry things at times. I'm a lucky dog. Peter Frinchaboy eventually became my adviser at Texas Christian University after asking Caty to suggest a graduate student. I say eventually because I resisted coming to a university in Texas, especially one with Christian in its name. Everyone makes mistakes. Peter has guided my graduate student career with both humor and honesty. There's always a nugget of truth in his humor, and always the flavor of humor in his honesty. I could not have asked for a better combination in an adviser. Thank you, Peter, for your persistence, for your humor, and for your honesty. As grateful as I am for the guidance and light from my adviser, all the educators and mentors on this journey, I would be sorely remiss if I let this opportunity pass without acknowledging my former graduate student peers. Not only were Sebastian Requena, Pankaj Kumar and Yui Shiozawa my battle comrades in coursework, they challenged iii me to fill the gaps in their astronomy knowledge, and shared their own application of physics with me. Joseph Campbell said, \If you can see your path laid out in front of you step by step, you know it's not your path. Your own path you make with every step you take. That's why it's your path." I think this is very true for all graduate students, so it's entirely reassuring to look over the tall grass to see others, too, struggling to cut their own paths. Battles are won and lost, but all the wins and losses become shared experiences in this process. It is forever my pleasure and honor to know them. My children, Sally and Danny, have probably sacrificed more than anyone to con- tribute to my journey. Even though both are adults with their own lives, I have missed a good chunk of time with them, their own struggles through adulthood, and missed many holidays and birthdays. They have no regrets, and could not have been more supportive. It speaks to me as much as the title. They call me Dr. Mom. I didn't think I could love them more. They proved me wrong. Wonderful. Finally, I cannot end this without giving credit to the two people in my life who, most likely, first put my feet on this path; my father and my brother. After Sputnik went up, my father built his own telescope, ground his own glass for it, and taught himself about light and stars. When my brother was eleven, my father bought him his own telescope, and the two would set off on clear nights to stargaze. I was allowed to tag along, probably because my brother, Bobby, desperately wanted a brother after the addition of his third sister, me. As the last in a line of sisters, I was his designated brother. Almost as soon as I could walk, Bobby dressed me in boy's clothes and took me along with him to hang out with friends. I was my brother's sidekick, and allowed access to his telescope without permission. He never called me little sister. Bobby always treated me as his equal. A gift. My father always bought me the `sciency' gifts for Christmas; the chemistry set, or the filter kit for polarizing light{ something along those lines. He taught me about color and light through photography, and walked me through the science kits to show me... possibilities. He also taught me to play chess, how to anticipate a strategy, when to trust my intuition, and when to reason past that intuition.