University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2006 Near-Infrared Observations Of Comet-Asteroid Transition Objects Julie Elaine Ziffer University of Central Florida Part of the Astrophysics and Astronomy Commons Find similar works at: https://stars.library.ucf.edu/etd University of Central Florida Libraries http://library.ucf.edu This Doctoral Dissertation (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Electronic Theses and Dissertations, 2004-2019 by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Ziffer, Julie Elaine, "Near-Infrared Observations Of Comet-Asteroid Transition Objects" (2006). Electronic Theses and Dissertations, 2004-2019. 6109. https://stars.library.ucf.edu/etd/6109 NEAR-INFRARED OBSERVATIONS OF COMET-ASTEROID TRANSITION OBJECTS by JULIE ELAINE ZIFFER M.S. Troy State University, 1997 B.S. Truman State University, 1994 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics in the College of Arts and Sciences at the University of Central Florida Orlando, Florida Summer Term 2006 Major Professor: Humberto Campins © 2006 Julie Elaine Ziffer ii ABSTRACT The primary objective of this research is to characterize the surface composition of five comet-asteroid transition objects via near-infrared spectroscopy. The five targets include two asteroids with Tisserand invariants lower than 3.0 (1373 Cincinnati and 2906 Caltech), one asteroid that is likely an extinct comet (944 Hidalgo), one intermittent activity comet (162P/Siding Spring), and one nearly dormant comet (28P/Neujmin1). Previous research regarding cometary end states and dynamical and physical properties of comets and asteroids provides the foundation for this work. Focusing primarily on the 1-2.5 µm spectral region of the five target objects, this project specifically searches for mineral species such as olivine, pyroxene, hydrated silicates, and organics. Comparisons are made with comets, main belt asteroids, and Trojan asteroids. All our targets have near-infrared spectra with varying “red” slopes from S'=1.7 to 5.3. Slopes in this range are characteristic of both primitive asteroids and comets. Three of our objects, 944 Hidalgo, 162P/Siding Spring, 28P/Neujmin 1, showed relatively featureless near-infrared spectra. The two objects dynamically most likely to be of asteroidal origin, 1373 Cincinnati and 2906 Caltech, both displayed features in the 0.8 to 2.5 micron range, not present in any of our other targets or the comparison cometary nuclei. Spectra of 944 Hidalgo were acquired at several rotational phases and clear rotational variations were found. Hints of spectral variability were also observed in 28P/Neujmin 1 and 162P/Siding Spring. Neither 1373 nor 2906 were iii examined for rotational variability. Based on our results, we believe that 1373 Cincinnatti and 2906 Caltech are not cometary. The spectral range of our targets and cometary spectra in the near-infrared is the same as that of Trojan asteroids. Recommendations for future investigation are suggested. iv To my Nana and Pop-Pop For giving me all the things that no one can ever take away. v ACKNOWLEDGMENTS This long process would not have been possible without both direct and indirect help from key people in my life. Humberto Campins my advisor and friend took me under his wing and has assisted me through every step of this process. This dissertation is now complete, but I have found a lifelong friend. Thanks to my entire committee (to include Humberto Campins, Yan Fernandez, Glenn Boreman and Dan Britt) for their patience, flexibility, approachability and above all allowing me to enjoy the journey and not just the destination. Thanks to the others who have assisted in the content of the dissertation including Carl Hergenrother for providing a lightcurve for one of the target objects, to Noemi Pinilla-Alonso for assistance with the modeling of my targets, to Richard Binzel and Javier Licandro for providing additional spectra of two targets, and to Bobby Bus for answering my questions regarding data reduction. Thanks Dr. Johnson: for a wonderful example of how to teach and for taking me to a “higher plane “of physics. Thanks also to Mr. L. Bigelow for awakening my inner physicist. To the other inspiring professors along the way including: A. Bhattacharya, H. Saha, R. Peale, E. Mucciolo, D. Walters, B. Marshall, and K. Douglas. Thanks to all my physics friends that kept me interested and alive: Scott Wasman for starting with me on my physics journey and being an amazing friend. Thanks to all the original crew: Frank Mackey for introducing me to the undergraduate room and a new world. Thanks also for the sanity check that grad school is better than a bunker in the desert. Travis Lau for allowing me to live vicariously through his adventures. Mike vi Duffy for Atlanta and all the great conversations, Kevin Demarco for really awesome politics, for allowing me into his life, and for helping me through the semester when Edyson was born. To Alan Tirpak, Lena Lopatiuk, and Gero Nootz - thanks for the tech center, all the invitations and parties, and for getting me through that horrible summer studying for the qualifier. Thanks to all of you for the hours and hours and hours of physics sparring. To the second wave of physics friends: Erin Langsdorf: thanks for holding my hand through the rough parts and getting me through that Table 1!!! Thanks to Rohit Desphande, Ramarao Tata, Sergio Tafur, Rick Lugo, Paul Gardner, John Fraine, Frank Mackey (again) and all the others for friendship and technical support. Additionally I would like to thank Malic Dekkar for his priceless computer aid during this endeavor. A special thanks must go to all my family and friends who have sustained me spiritually, emotionally, and physically and helped me to reach this goal. First I must thank my family who, on a daily basis, replenished my strength. Every night I peacefully slept knowing that no matter the hardships to come, Emily, Edyson and Aria would be beside me offering the opportunity to love them and share another day with them. They provided purpose to get up in the morning and to strive to make each day count. The happiness and innocence of Edyson and Aria deepens my spirit and provides me peace. For Emily’s generosity and love I am forever indebted… I can’t wait to repay in lifetimes of laughter, support, sharing, and living. Thanks to my Mom and Dad for starting me on a solid strong path and for being tolerant of my occasionally large error bars. A more specific thanks to Mom for continuing the tradition of weekend after weekend of hard work in creating this vii manuscript. Your help will not be forgotten. Thanks to my sister for always lending a supportive ear when I needed it. Thanks to my Nana who led me by example and provided me the courage to be audacious and steadfast. Thanks to my PopPop, who passed away the morning of my defense, for: teaching me the value of math and instilling a curiosity and love of all physical science. My grandparents were so influential in my education that I have chosen to dedicate this manuscript to them “I always knew that looking back on us crying would make me laugh, but I never realized that looking back on us laughing would make me cry.” And to all the remaining family and friends who have helped me on this journey, you know who you are and all the ways you have helped: Shane, Mikayla, Tyler, Uncle Ted and Uncle Dick, Matthew W., Doris and Ed, Ivy, David, Danielle, Matthew, Alanna, Arthur, Michelle, Hayley, Larry, Melissa , Isaac, Aunt Judy and Uncle Jack, Daniel and JJ. And finally, thanks to all the other people and things that have otherwise influenced and affected me along the way- the products of this work extend far beyond this manuscript. viii TABLE OF CONTENTS LIST OF FIGURES.........................................................................................................xii LIST OF TABLES...........................................................................................................xv CHAPTER 1 – INTRODUCTION..................................................................................... 1 1.1 Overview of Solar System .................................................................................... 1 1.1.1 Comets.......................................................................................................... 2 1.1.2 Asteroids ........................................................................................................ 3 1.1.3 Comet-Asteroid Transition Objects ................................................................ 6 1.2 Objective and Technique ...................................................................................... 7 1.3 Thesis layout......................................................................................................... 9 CHAPTER 2 - LITERATURE REVIEW.......................................................................... 10 2.1 Cometary End States.......................................................................................... 10 2.1.1 Random Disruption: ..................................................................................... 11 2.1.2 Non-Volatile Crust: ....................................................................................... 11 2.1.3 Evidence for Extinct Comets in the Near-Earth-Object Population:.............