subject:( Binary Stars )

Rochester Institute of Technology

1. Wilson, Emily C. Convection in Common Envelopes.

Degree: MS, School of Physics and Astronomy (COS), 2019, Rochester Institute of Technology

URL: https://scholarworks.rit.edu/theses/9986

► The outcomes of stellar evolution can be significantly affected by the presence of close substellar or stellar companions. Common envelopes (CE) are thought to… (more)

Subjects/Keywords: AGB stars; Binary stars; Convection

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APA (6^th Edition):

Wilson, E. C. (2019). Convection in Common Envelopes. (Masters Thesis). Rochester Institute of Technology. Retrieved from https://scholarworks.rit.edu/theses/9986

Chicago Manual of Style (16^th Edition):

Wilson, Emily C. “Convection in Common Envelopes.” 2019. Masters Thesis, Rochester Institute of Technology. Accessed March 07, 2021. https://scholarworks.rit.edu/theses/9986.

MLA Handbook (7^th Edition):

Wilson, Emily C. “Convection in Common Envelopes.” 2019. Web. 07 Mar 2021.

Vancouver:

Wilson EC. Convection in Common Envelopes. [Internet] [Masters thesis]. Rochester Institute of Technology; 2019. [cited 2021 Mar 07]. Available from: https://scholarworks.rit.edu/theses/9986.

Council of Science Editors:

Wilson EC. Convection in Common Envelopes. [Masters Thesis]. Rochester Institute of Technology; 2019. Available from: https://scholarworks.rit.edu/theses/9986

University of Arizona

2. Smullen, Rachel Ann. The Formation and Early Evolution of Binaries and their Environments .

Degree: 2020, University of Arizona

URL: http://hdl.handle.net/10150/642017

► Binaries—two bodies of comparable mass that orbit a common center—influence the evolution of gas and planets in their vicinity and are ubiquitous in star and… (more)

▼ Binaries—two bodies of comparable mass that orbit a common center—influence the evolution of gas and planets in their vicinity and are ubiquitous in star and planet formation. And yet, because of the complexity binaries add to already complex problems, they have often been excluded from consideration in theoretical and observational work. In this dissertation, I present an exploration of the formation and early evolution of binaries and their environments in four contexts: debris in the Pluto-Charon system, dynamics in the Kuiper Belt of our Solar System, planetary systems around binary stars, and variability in star-forming cores. First, I explore the fate of debris that could have resulted from the giant impact origin of the Pluto-Charon dwarf planet binary to look for observational signatures of its formation that may persist to this day. Using N-body simulations, I estimate the cratering rates on Charon's surface that would result from collisions of small debris from the post-formation debris disk, and I also make predictions for the presence of a Pluto-Charon disk collisional family of debris that were ejected from the binary that may still be orbiting in the Kuiper Belt today. Second, I develop a machine learning algorithm to quickly and accurately classify the dynamical population membership of observed Kuiper Belt objects. Current classification methodologies require substantial human intervention, and with imminent surveys expected to increase the number of known Kuiper Belt objects by an order of magnitude, automated methods are required. I find good accuracy in my method and characterize the reasons the algorithm can fail, including object rarity and the inherent ambiguity of classification in a time-dependent system. Third, I simulate the dynamical evolution of the planet populations around both single and binary stars to understand the influence of a close central binary on planetary system architecture. I find that a central binary only changes the planet loss mechanism: planets around a binary are much more likely to suffer a catastrophic interaction with the binary and be ejected from the system rather than undergoing a more gentle scattering that can lead to collisions. Instead, the system architecture is primarily driven by the most massive planet in the system regardless of the central object. Finally, I study the time evolution of dense, star-forming cores using magnetohydrodynamical simulations. I create an algorithm to link cores through time, and I find that the structures we identify can have large variability in extracted quantities (such as mass) in time despite the distributions of those quantities remaining stable. I postulate that a large fraction of the variability could come from the structure identification algorithms, which rely upon relative measures of structure that can change in time. Advisors/Committee Members: Kratter, Kaitlin M (advisor), Malhotra, Renu (committeemember), Najita, Joan R. (committeemember), Shirley, Yancy L. (committeemember), Smith, Nathan (committeemember).

Subjects/Keywords: Binary stars; Dynamics; Planets

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APA (6^th Edition):

Smullen, R. A. (2020). The Formation and Early Evolution of Binaries and their Environments . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/642017

Chicago Manual of Style (16^th Edition):

Smullen, Rachel Ann. “The Formation and Early Evolution of Binaries and their Environments .” 2020. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/642017.

MLA Handbook (7^th Edition):

Smullen, Rachel Ann. “The Formation and Early Evolution of Binaries and their Environments .” 2020. Web. 07 Mar 2021.

Vancouver:

Smullen RA. The Formation and Early Evolution of Binaries and their Environments . [Internet] [Doctoral dissertation]. University of Arizona; 2020. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/642017.

Council of Science Editors:

Smullen RA. The Formation and Early Evolution of Binaries and their Environments . [Doctoral Dissertation]. University of Arizona; 2020. Available from: http://hdl.handle.net/10150/642017

University of Manchester

3. Tyndall, Amy. A study of planetary nebulae possessing binary central stars.

Degree: PhD, 2014, University of Manchester

URL: https://www.research.manchester.ac.uk/portal/en/theses/a-study-of-planetary-nebulae-possessing-binary-central-stars(2a326452-82b4-4749-931d-5c3b6cf051a4).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617959

► In this thesis, detailed studies of three different types of binary central stars withinplanetary nebulae (bCSPNe) are presented, with the aim of investigating the effectssuch… (more)

▼ In this thesis, detailed studies of three different types of binary central stars withinplanetary nebulae (bCSPNe) are presented, with the aim of investigating the effectssuch a range of binary systems has on the morphology and kinematics of the surroundingnebulae, as well as discussing what the implication is for the interaction betweenthe stars themselves. A close binary, an intermediate period binary, and a compactbinary system are examined. The close binary PN HaTr 4 is the first system to be studied via detailed spatiokinematicalanalysis and modelling, and it is one of few known to contain a postcommonenvelope (CE) central star system. CE evolution is believed to play an importantrole in the shaping of PNe, but the exact nature of this role is yet to be understood. High spatial and spectral resolution spectroscopy is presented alongside deep narrowbandimagery to derive the three-dimensional morphology of HaTr 4. The nebula isfound to display an extended ovoid morphology with an enhanced equatorial regionconsistent with a toroidal waist - a feature believed to be typical amongst PNe withpost-CE central stars. The nebular symmetry axis is found to lie perpendicular to theorbital plane of the central binary, concordant with the idea that the formation andevolution of HaTr 4 has been strongly influenced by its central binary. Next, PN LoTr 1 is studied using a combination of spectra and photometry, andis thought to contain an intermediate-period binary central star system (P = 100–1500d). Here, we confirm the binary nature of the central star of LoTr 1, consisting of aK1 III star and a hot white dwarf (WD). The nebula of LoTr 1 presents a very differentmorphology than that of other seemingly similar bCSPNe possessing barium stars,A70 and WeBo 1 (included in this study for direct comparison), which may be anindication of a difference in their mass-transfer episodes. There is no evidence ofbarium enhancement in the K1 III companion, but it is shown to have a rotation periodof 6.4 d which is most likely a sign of mass accretion. Such a system represents arare opportunity to further the investigation into the formation of barium stars andintermediate period, post-asymptotic giant branch (AGB) systems. Finally, the first analysis of an object from the new POPIPlaN catalogue of PNe ispresented. Photometry of the central star system of PN G033.8+01.5 showed it to bea compact binary of P = 0.1268 d, consisting of a cool M2 V main sequence star anda hot WD surrounded by a very asymmetric PN. The very short orbital period leadsto the possibility of PN G033.8+01.5 being a cataclysmic variable candidate, which inturn leads to the question of whether the visible nebulous material is that of a true PNor if it is the remnant of an outburst.

Subjects/Keywords: 523.1; Planetary nebulae; Binary stars

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APA (6^th Edition):

Tyndall, A. (2014). A study of planetary nebulae possessing binary central stars. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/a-study-of-planetary-nebulae-possessing-binary-central-stars(2a326452-82b4-4749-931d-5c3b6cf051a4).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617959

Chicago Manual of Style (16^th Edition):

Tyndall, Amy. “A study of planetary nebulae possessing binary central stars.” 2014. Doctoral Dissertation, University of Manchester. Accessed March 07, 2021. https://www.research.manchester.ac.uk/portal/en/theses/a-study-of-planetary-nebulae-possessing-binary-central-stars(2a326452-82b4-4749-931d-5c3b6cf051a4).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617959.

MLA Handbook (7^th Edition):

Tyndall, Amy. “A study of planetary nebulae possessing binary central stars.” 2014. Web. 07 Mar 2021.

Vancouver:

Tyndall A. A study of planetary nebulae possessing binary central stars. [Internet] [Doctoral dissertation]. University of Manchester; 2014. [cited 2021 Mar 07]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/a-study-of-planetary-nebulae-possessing-binary-central-stars(2a326452-82b4-4749-931d-5c3b6cf051a4).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617959.

Council of Science Editors:

Tyndall A. A study of planetary nebulae possessing binary central stars. [Doctoral Dissertation]. University of Manchester; 2014. Available from: https://www.research.manchester.ac.uk/portal/en/theses/a-study-of-planetary-nebulae-possessing-binary-central-stars(2a326452-82b4-4749-931d-5c3b6cf051a4).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617959

University of Texas – Austin

4. -9056-2052. Spectroscopic detection and characterization of extreme flux-ratio binary systems.

Degree: PhD, Astronomy, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/39460

► Binary stars and higher-order multiple systems are a ubiquitous outcome of star formation, especially as the system mass increases. The companion mass-ratio distribution is a… (more)

Subjects/Keywords: Binary stars; Star formation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-9056-2052. (2016). Spectroscopic detection and characterization of extreme flux-ratio binary systems. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/39460

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16^th Edition):

-9056-2052. “Spectroscopic detection and characterization of extreme flux-ratio binary systems.” 2016. Doctoral Dissertation, University of Texas – Austin. Accessed March 07, 2021. http://hdl.handle.net/2152/39460.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7^th Edition):

-9056-2052. “Spectroscopic detection and characterization of extreme flux-ratio binary systems.” 2016. Web. 07 Mar 2021.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-9056-2052. Spectroscopic detection and characterization of extreme flux-ratio binary systems. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2016. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2152/39460.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-9056-2052. Spectroscopic detection and characterization of extreme flux-ratio binary systems. [Doctoral Dissertation]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/39460

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Columbia University

5. Andrews, Jeffrey. Double White Dwarfs as Probes of Single and Binary Star Evolution.

Degree: 2016, Columbia University

URL: https://doi.org/10.7916/D8VH5NQ4

► As the endpoints of stars less massive than roughly eight solar masses, the population of Galactic white dwarfs (WD) contain information about complex stellar evolution… (more)

▼ As the endpoints of stars less massive than roughly eight solar masses, the population of Galactic white dwarfs (WD) contain information about complex stellar evolution processes. Associated pairs of WDs add an extra degree of leverage; both WDs must have formed and evolved together. The work presented in this dissertation uses various populations of double WDs (DWD) to constrain evolution of both single and binary stars. One example is the set of low-mass WDs with unseen WD companions, which are formed through a dynamically-unstable mass loss process called the common envelope. To work toward a quantitative understanding of the common envelope, we develop and apply a Bayesian statistical technique to identify the masses of the unseen WD companions. We provide results which can be compared to evolutionary models and hence a deeper understanding of how binary stars evolve through a common envelope. The statistical technique we develop can be applied to any population of single-line spectroscopic binaries. Binaries widely separated enough that they avoid any significant interaction independently evolve into separate WDs that can be identified in photometric and astrometric surveys. We discuss techniques for finding these objects, known as wide DWDs. We present a catalog of 142 candidate wide DWDs, combining both previously detected systems and systems we identify in our searches in the Sloan Digital Sky Survey. Having been born at the same time, the masses and cooling ages of the WDs in wide DWDs, obtained with our spectroscopic follow-up campaign can be used to constrain the initial-final mass relation, which relates a main sequence star to the mass of the WD into which it will evolve. We develop a novel Bayesian technique to interpret our data and present our resulting constraints on this relation which are particularly strong for initial masses between two and four solar masses. During this process, we identified one wide DWD, HS 2220+2146, that was peculiar since the more massive WD in this system evolved second. We construct an evolutionary formation scenario in which the system began as a hierarchical triple in which the inner binary merged (possibly due to Kozai-Lidov oscillations) forming a post-blue straggler binary. The system then evolved into the DWD we observe today. We further discuss the potential for identifying more wide DWDs, including peculiar systems like HS 2220+2146, in future surveys such as Gaia.

Subjects/Keywords: White dwarf stars; Binary stars; Stars – Evolution; Astronomy; Astrophysics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Andrews, J. (2016). Double White Dwarfs as Probes of Single and Binary Star Evolution. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8VH5NQ4

Chicago Manual of Style (16^th Edition):

Andrews, Jeffrey. “Double White Dwarfs as Probes of Single and Binary Star Evolution.” 2016. Doctoral Dissertation, Columbia University. Accessed March 07, 2021. https://doi.org/10.7916/D8VH5NQ4.

MLA Handbook (7^th Edition):

Andrews, Jeffrey. “Double White Dwarfs as Probes of Single and Binary Star Evolution.” 2016. Web. 07 Mar 2021.

Vancouver:

Andrews J. Double White Dwarfs as Probes of Single and Binary Star Evolution. [Internet] [Doctoral dissertation]. Columbia University; 2016. [cited 2021 Mar 07]. Available from: https://doi.org/10.7916/D8VH5NQ4.

Council of Science Editors:

Andrews J. Double White Dwarfs as Probes of Single and Binary Star Evolution. [Doctoral Dissertation]. Columbia University; 2016. Available from: https://doi.org/10.7916/D8VH5NQ4

6. Papageorgiou, Athanasios. Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa.

Degree: 2015, University of Patras; Πανεπιστήμιο Πατρών

URL: http://hdl.handle.net/10442/hedi/35650

► The study of eclipsing binary systems remains one of the most powerful research fields in stellar astrophysics because it provides the primary source of calculating… (more)

▼ The study of eclipsing binary systems remains one of the most powerful research fields in stellar astrophysics because it provides the primary source of calculating fundamentals properties of stars (masses, radii, temperatures) and every form of stellar activity (spots, accreting discs, pulsations) through photometry and spectroscopy or/and through the study of long-term variability of their period. Additionally it allows testing of stellar structure and evolution theories and the prediction of third body companions of stellar or sub-stellar origin. This thesis is focused on the study of W UMa type eclipsing binaries containing main sequence stars in overcontact configuration with short periods and,therefore the small angular momentum. The aim is both the multiband observational study, analysis and investigation of WUMa systems of particular interest but also the development of modeling methodology in order to extract the maximum information and to determine a detailed assessment of the parameter uncertainties through the application of modern statistical methods. The first part of the Doctoral Thesis outlines the theoretical framework for describing eclipsing binary stars. Chapter 1 refers to the physics and geometry of orbits and components, the description of the Roche model that led to the classification based on equipotential surfaces, the computation of the total radiated flux in the direction of the observer by including all the corrections needed and the description of systems dynamics as manifested by the observed change of their period. Chapter2 presents the photometric observations made during this research and the automated methods of processing and analysis (pipelines) which were developed. Chapter 3 sketches the modern modeling and analysis software techniques for the solution of inverse problem(Differential Corrections, Levenberg-Marquardt, Downhill Simplex, Genetic Algorithms,Heuristic Scanning, Bootstrap resampling, Metropolis –Hasting Markov Chain MonteCarlo), their implementation to programs developed as part of the present thesis and their application to real data. These also represent the methodology of the analyses implemented for the study of the WUMa systems, described in Part 2. Finally, Chapter4 describes the development of a pipeline for the exploration, extraction and automatic analysis of data from astronomical surveys and its application to ASAS database. In the same chapter the first results from the training and validation of the Artificial Neural Network (ANN), EBAI, and the best topology for the ANN are presented.The second part focuses on the detailed study of selected W UMa systems with particular interest. This includes: the new multiband photometric observations, the longterm period variation, the exported model from photometric and spectroscopic data (from the literature), the determination of orbital and physical parameters and their position in evolutionary diagrams, the investigation of the proposed model for uniqueness in the parameter space through heuristic scanning with…

Subjects/Keywords: Διπλά εκλειπτικά συστήματα αστέρων; Eclipsing binary stars

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APA (6^th Edition):

Papageorgiou, A. (2015). Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa. (Thesis). University of Patras; Πανεπιστήμιο Πατρών. Retrieved from http://hdl.handle.net/10442/hedi/35650

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Papageorgiou, Athanasios. “Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa.” 2015. Thesis, University of Patras; Πανεπιστήμιο Πατρών. Accessed March 07, 2021. http://hdl.handle.net/10442/hedi/35650.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Papageorgiou, Athanasios. “Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa.” 2015. Web. 07 Mar 2021.

Vancouver:

Papageorgiou A. Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa. [Internet] [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2015. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10442/hedi/35650.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Papageorgiou A. Μελέτη και μοντελοποίηση διπλών εκλειπτικών συστημάτων αστέρων τύπου W UMa. [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2015. Available from: http://hdl.handle.net/10442/hedi/35650

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

7. Barker, John. Driving mechanisms for cataclysmic variable evolution.

Degree: PhD, 2003, Open University

URL: http://oro.open.ac.uk/62828/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289006

► Cataclysmic variables are interacting binary systems in which the evolution of the system is driven by the loss of orbital angular momentum. In this thesis… (more)

▼ Cataclysmic variables are interacting binary systems in which the evolution of the system is driven by the loss of orbital angular momentum. In this thesis I investigate possible angular momentum loss mechanisms and try to reconcile the differences between the observed and theoretically predicted minimum period and the orbital period distribution for systems with orbital periods below the period gap. Specifically I use a general consequential angular momentum loss mechanism (CAML) which depends linearly upon the mass transfer rate in the system, and a deformation mechanism which bloats the donor star. Numerical models to include the effects of circumbinary discs and irradiation driven winds from the donor star on the evolution of CVs were developed, the circumbinary disc model is able to raise the minimum period to the observed value. Systems subject to irradiation driven winds and high CAML efficiencies exhibit mass transfer cycles; these could explain the range of mass transfer rates observed in CVs with similar orbital periods. I also consider the possibility that the observed minimum period is purely an age effect. I model possible parent distributions by using an additional intrinsic angular momentum loss to set the minimum period to the observed value, with different spectra of donor star masses, white dwarf masses, efficiencies for the CAML and bloating mechanisms. A statistical test was developed and used to calculate a probability that the observed distribution is drawn from the modelled parent distribution. None of the calculated distributions gives a better fit than that for a flat distribution. This is suggestive of some additional evolutionary mechanism or selection effect. I also investigate the apparent difference between the distributions of magnetic and non-magnetic CVs over the period range (1.3 ≤ <i>P/hr</i> ≤ 15), concluding that it is likely that these systems evolve via different mechanisms for orbital periods above the lower edge of the period gap.

Subjects/Keywords: 523.844; Binary stars

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Barker, J. (2003). Driving mechanisms for cataclysmic variable evolution. (Doctoral Dissertation). Open University. Retrieved from http://oro.open.ac.uk/62828/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289006

Chicago Manual of Style (16^th Edition):

Barker, John. “Driving mechanisms for cataclysmic variable evolution.” 2003. Doctoral Dissertation, Open University. Accessed March 07, 2021. http://oro.open.ac.uk/62828/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289006.

MLA Handbook (7^th Edition):

Barker, John. “Driving mechanisms for cataclysmic variable evolution.” 2003. Web. 07 Mar 2021.

Vancouver:

Barker J. Driving mechanisms for cataclysmic variable evolution. [Internet] [Doctoral dissertation]. Open University; 2003. [cited 2021 Mar 07]. Available from: http://oro.open.ac.uk/62828/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289006.

Council of Science Editors:

Barker J. Driving mechanisms for cataclysmic variable evolution. [Doctoral Dissertation]. Open University; 2003. Available from: http://oro.open.ac.uk/62828/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289006

Universiteit Utrecht

8. Bonačić Marinović, A.A. Nucleosynthesis and evolution of AGB stars in binary systems.

Degree: 2007, Universiteit Utrecht

URL: http://dspace.library.uu.nl:8080/handle/1874/23521

► Thermally-pulsating asymptotic giant branch (TP-AGB) stars are hundreds of times larger and several tens of thousand times more luminous than than the Sun. They are… (more)

▼ Thermally-pulsating asymptotic giant branch (TP-AGB) stars are hundreds of times larger and several tens of thousand times more luminous than than the Sun. They are composed of a compact carbon and oxygen core and an extended hydrogen convective envelope. These stars are intermediate-mass objects in their last stages of evolution, just before they die as a cooling compact star called a white dwarf. TP-AGB stars are the main producers of slow neutron capture (s-) process elements, which are elements heavier than iron such as strontium, yttrium, zirconium, caesium, barium, lanthanum and cerium. There are still large uncertainties associated with the formation of the main neutron source needed for the synthesis of these elements and with the physics of these stars in general. Observations of s-process element enhancements in stars can be used as constraints on theoretical models. For the first time we apply stellar population synthesis to the problem of s-process nucleosynthesis in TP-AGB stars and have constrained the free parameters describing the physics of the mixing process of these elements into the stellar envelope and the properties of the neutron source. We show that the amount of 13C which effectively contributes as a neutron source to s-process element synthesis tends to decrease with metallicity and that it is constrained to a narrower range of values than that previously believed. We also find that the mixing of s-process elements into the stellar envelope happens in stars of lower initial mass than those predicted by theoretical models. Binary systems which contained a TP-AGB star, now observed as a white dwarf, show significant orbital eccentricity. However, the strong tidal interaction which should have taken place due to the large size of a TP-AGB star must have dissipated significant amounts of energy and consequently circularised the orbit. This indicates that a mechanism which enhances the orbital eccentricity must take place in order to explain the observations. We propose a model for TP-AGB stars in binary systems in which their mass-loss is enhanced when the system components are closer to each other. This uneven mass-loss along the orbit provides a mechanism which enhances the orbital eccentricity in such a way that it competes with the tidal circularisation. We show that by applying this mechanism it is possible to explain the eccentric orbit of systems such as Sirius and of many barium stars, which so far had no explanation under the standard assumptions considering only tidal dissipation.

Subjects/Keywords: Natuur- en Sterrenkunde; stars: AGB and post-AGB; stars; abundances; nucleosynthesis; stars: binary; stars: evolution; stars: Sirius

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bonačić Marinović, A. A. (2007). Nucleosynthesis and evolution of AGB stars in binary systems. (Doctoral Dissertation). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/23521

Chicago Manual of Style (16^th Edition):

Bonačić Marinović, A A. “Nucleosynthesis and evolution of AGB stars in binary systems.” 2007. Doctoral Dissertation, Universiteit Utrecht. Accessed March 07, 2021. http://dspace.library.uu.nl:8080/handle/1874/23521.

MLA Handbook (7^th Edition):

Bonačić Marinović, A A. “Nucleosynthesis and evolution of AGB stars in binary systems.” 2007. Web. 07 Mar 2021.

Vancouver:

Bonačić Marinović AA. Nucleosynthesis and evolution of AGB stars in binary systems. [Internet] [Doctoral dissertation]. Universiteit Utrecht; 2007. [cited 2021 Mar 07]. Available from: http://dspace.library.uu.nl:8080/handle/1874/23521.

Council of Science Editors:

Bonačić Marinović AA. Nucleosynthesis and evolution of AGB stars in binary systems. [Doctoral Dissertation]. Universiteit Utrecht; 2007. Available from: http://dspace.library.uu.nl:8080/handle/1874/23521

Columbia University

9. Sandford, Emily Ruth. The Shapes of Planet Transits and Planetary Systems.

Degree: 2020, Columbia University

URL: https://doi.org/10.7916/d8-jqt7-9a41

► In this Thesis, I explore transiting exoplanets: what we can learn from modeling their light curves, and what we can learn from their arrangement in… (more)

▼ In this Thesis, I explore transiting exoplanets: what we can learn from modeling their light curves, and what we can learn from their arrangement in planetary systems. I begin in Chapter 1 by briefly reviewing the history of transit modeling, from the earliest theoretical models of eclipsing binary stars to the models in current widespread use to model exoplanet transits. In Chapter 2, I model the transits of a sample of Kepler exoplanets with strong prior eccentricity constraints in order to derive correspondingly strong constraints on the density of their host stars, and find that the density constraints I derive are as precise as density constraints from asteroseismology if the transits are observed at high signal-to-noise. In Chapter 3, I apply the same methodology in reverse: using prior knowledge of the stellar density based on Gaia parallax measurements, I model the transits of twelve singly-transiting planets observed by K2 and derive constraints on their periods. In Chapter 4, I consider the general problem of deducing the shape of a transiting object from its light curve alone, which I term ``shadow imaging;'' I explore the mathematical degeneracies of the problem and construct shadow images to explain Dips 5 and 8 of Boyajian's Star. I next turn to multi-planet systems: in Chapter 5, I investigate the underlying multiplicity distribution of planetary systems orbiting FGK dwarfs observed by Kepler. I find that we can explain the multiplicities of these systems with a single Zipfian multiplicity distribution, without invoking a dichotomous population. In Chapter 6, I consider the arrangement of planets in those systems, and use neural networks inspired by models used for part-of-speech tagging in computational linguistics to model the relationship between exoplanets and their surrounding "context," i.e. their host star and sibling planets. I find that our trained regression model is able to predict the period and radius of an exoplanet to a factor of two better than a naive model which only takes into account basic dynamical stability. I also find that our trained classification model identifies consistent classes of planets in the period-radius plane, and that it is rare for multi-planet systems to contain a neighboring pair of planets from non-contiguous classes. In Chapter 7, I summarize these results and briefly discuss avenues for future work, including the application of our methods to planets and planetary systems discovered by TESS.

Subjects/Keywords: Astronomy; Extrasolar planets; Light curves; Planets – Transits; Dwarf stars; Binary stars

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APA (6^th Edition):

Sandford, E. R. (2020). The Shapes of Planet Transits and Planetary Systems. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/d8-jqt7-9a41

Chicago Manual of Style (16^th Edition):

Sandford, Emily Ruth. “The Shapes of Planet Transits and Planetary Systems.” 2020. Doctoral Dissertation, Columbia University. Accessed March 07, 2021. https://doi.org/10.7916/d8-jqt7-9a41.

MLA Handbook (7^th Edition):

Sandford, Emily Ruth. “The Shapes of Planet Transits and Planetary Systems.” 2020. Web. 07 Mar 2021.

Vancouver:

Sandford ER. The Shapes of Planet Transits and Planetary Systems. [Internet] [Doctoral dissertation]. Columbia University; 2020. [cited 2021 Mar 07]. Available from: https://doi.org/10.7916/d8-jqt7-9a41.

Council of Science Editors:

Sandford ER. The Shapes of Planet Transits and Planetary Systems. [Doctoral Dissertation]. Columbia University; 2020. Available from: https://doi.org/10.7916/d8-jqt7-9a41

10. Parihar, Padmakar Singh. A photometric study of RS CVn binary stars; -.

Degree: Physics, 2000, Pt. Ravishankar Shukla University

URL: http://shodhganga.inflibnet.ac.in/handle/10603/50194

Available

Bibliography given

Advisors/Committee Members: Pandey, S K.

Subjects/Keywords: Binary stars; photometric study; Stars

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APA (6^th Edition):

Parihar, P. S. (2000). A photometric study of RS CVn binary stars; -. (Thesis). Pt. Ravishankar Shukla University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/50194

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Parihar, Padmakar Singh. “A photometric study of RS CVn binary stars; -.” 2000. Thesis, Pt. Ravishankar Shukla University. Accessed March 07, 2021. http://shodhganga.inflibnet.ac.in/handle/10603/50194.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Parihar, Padmakar Singh. “A photometric study of RS CVn binary stars; -.” 2000. Web. 07 Mar 2021.

Vancouver:

Parihar PS. A photometric study of RS CVn binary stars; -. [Internet] [Thesis]. Pt. Ravishankar Shukla University; 2000. [cited 2021 Mar 07]. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/50194.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Parihar PS. A photometric study of RS CVn binary stars; -. [Thesis]. Pt. Ravishankar Shukla University; 2000. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/50194

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

11. Wallace, Daniel B. An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry.

Degree: MS, Space Studies, 2015, University of North Dakota

URL: https://commons.und.edu/theses/1849

► Continued observation of double stars is necessary for confirmation of binarity and to provide updates to astrometric data used to compute accurate binary orbital… (more)

▼ Continued observation of double stars is necessary for confirmation of binarity and to provide updates to astrometric data used to compute accurate binary orbital parameters, thereby more accurately informing stellar mass estimations – the critical parameter from which stellar models are derived. In October of 2013, six double stars from the Washington Double Star (WDS) catalog exhibiting close separations, as well as significant deviations from previously published orbits, were observed and imaged using the speckle interferometric technique on the 2.1-meter telescope at Kitt Peak National Observatory (KPNO) in Arizona. The observations of the six double stars occurred as part of large, collaborative, eight-night, student-learning-centered observing run organized by principal investigator Genet of California Polytechnic Institute. The run produced in total roughly 1000 raw speckle images for each of the more than 1000 double stars and single reference stars observed, resulting in a total database of 1.4 terabytes. The speckle images for the targets, including the six targets investigated in this thesis, were taken using a relatively low-cost, portable speckle interferometry camera system developed by Genet, the heart of which is a lightweight, high speed, high signal to noise ratio (SNR) Andor electron multiplying CCD (EMCCD) camera capable of exposures on the order of tens of milliseconds. Exposures of 10-20 milliseconds are faster than atmospheric coherence timescales, and allow for the implementation of the speckle interferometry – the obtainment of diffraction-limited image information of binary stars defined by the full aperture of the telescope from the autocorrelation and Fourier analysis of randomly distributed, isoplanatically correlated speckle pairs, which represent the diffraction-limited images of the associated coherence cells above and within the atmospheric area of the primary aperture (sub-apertures). Following the Oct. 2013 observing run, reduction and analysis of the speckle images for the six target binary stars (as well as five calibration binaries) and determination of the new astrometry was completed using the general purpose astrometry software program PlateSolve3 (PS3), written and developed by Rowe & Genet (2014). Using the new astrometric data derived from the Oct. 2013 2.1-meter speckle observations, the previously published United States Naval Observatory (USNO) orbital plots for the six target doubles were updated to reflect the new, and in some cases missing measurements. Target double star orbits were reevaluated in light of the updates in order to draw conclusions about the characteristics of each proposed binary system. In all six target cases, continued trends in significant astrometric deviations from published orbits and ephemerides have been demonstrated by the new observations, indicating the need for orbital revisions of these binaries. Analysis of systems WDS22357+5413, WDS02231+7021, and WDS06256+2227 indicate rectilinear rather than Keplerian motion, and are… Advisors/Committee Members: Paul S. Hardersen.

Subjects/Keywords: 2.1-meter Telescope; Binary Stars; Double Stars; Speckle Interferometry

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APA (6^th Edition):

Wallace, D. B. (2015). An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry. (Masters Thesis). University of North Dakota. Retrieved from https://commons.und.edu/theses/1849

Chicago Manual of Style (16^th Edition):

Wallace, Daniel B. “An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry.” 2015. Masters Thesis, University of North Dakota. Accessed March 07, 2021. https://commons.und.edu/theses/1849.

MLA Handbook (7^th Edition):

Wallace, Daniel B. “An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry.” 2015. Web. 07 Mar 2021.

Vancouver:

Wallace DB. An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry. [Internet] [Masters thesis]. University of North Dakota; 2015. [cited 2021 Mar 07]. Available from: https://commons.und.edu/theses/1849.

Council of Science Editors:

Wallace DB. An Investigation Of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry. [Masters Thesis]. University of North Dakota; 2015. Available from: https://commons.und.edu/theses/1849

Queens University

12. Shultz, Matthew. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .

Degree: Physics, Engineering Physics and Astronomy, 2016, Queens University

URL: http://hdl.handle.net/1974/14691

► How do the magnetic fields of massive stars evolve over time? Are their gyrochronological ages consistent with ages inferred from evolutionary tracks? Why do most… (more)

▼ How do the magnetic fields of massive stars evolve over time? Are their gyrochronological ages consistent with ages inferred from evolutionary tracks? Why do most stars predicted to host Centrifugal Magnetospheres (CMs) display no Hα emission? Does plasma escape from CMs via centrifugal breakout events, or by a steady-state leakage mechanism? This thesis investigates these questions via a population study with a sample of 51 magnetic early B-type stars. The longitudinal magnetic field \bz~was measured from Least Squares Deconvolution profiles extracted from high-resolution spectropolarimetric data. New rotational periods P_rot were determined for 15 stars from \bz, leaving only 3 stars for which P_rot is unknown. Projected rotational velocities \vsini~were measured from multiple spectral lines. Effective temperatures and surface gravities were measured via ionization balances and line profile fitting of H Balmer lines. Fundamental physical parameters, \bz, \vsini, and P_rot were then used to determine radii, masses, ages, dipole oblique rotator model, stellar wind, magnetospheric, and spindown parameters using a Monte Carlo approach that self-consistently calculates all parameters while accounting for all available constraints on stellar properties. Dipole magnetic field strengths B_d follow a log-normal distribution similar to that of Ap stars, and decline over time in a fashion consistent with the expected conservation of fossil magnetic flux. P_rot increases with fractional main sequence age, mass, and B_d, as expected from magnetospheric braking. However, comparison of evolutionary track ages to maximum spindown ages t_S,max shows that initial rotation fractions may be far below critical for stars with M_*>10 M_\odot. Computing t_S,max with different mass-loss prescriptions indicates that the mass-loss rates of B-type stars are likely much lower than expected from extrapolation from O-type stars. Stars with Hα in emission and absorption occupy distinct regions in the updated rotation-magnetic confinement diagram: Hα-bright stars are found to be younger, more rapidly rotating, and more strongly magnetized than the general population. Emission strength is sensitive both to the volume of the CM and to the mass-loss rate, favouring leakage over centrifugal breakout.

Subjects/Keywords: Stellar Winds ; Binary Stars ; Magnetospheres ; Massive Stars ; Magnetic Braking ; Stellar Magnetism ; Spectropolarimetry

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APA (6^th Edition):

Shultz, M. (2016). The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/14691

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Shultz, Matthew. “The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .” 2016. Thesis, Queens University. Accessed March 07, 2021. http://hdl.handle.net/1974/14691.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Shultz, Matthew. “The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .” 2016. Web. 07 Mar 2021.

Vancouver:

Shultz M. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . [Internet] [Thesis]. Queens University; 2016. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1974/14691.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Shultz M. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . [Thesis]. Queens University; 2016. Available from: http://hdl.handle.net/1974/14691

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Princeton University

13. Pjanka, Patryk. Cataclysmic Variables in MHD .

Degree: PhD, 2020, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp01v405sd437

► We present results of global magnetohydrodynamic (MHD) simulations of accretion disks in Cataclysmic Variables fed by Roche lobe overflow, including vertical stratification, in order to… (more)

▼ We present results of global magnetohydrodynamic (MHD) simulations of accretion disks in Cataclysmic Variables fed by Roche lobe overflow, including vertical stratification, in order to investigate the roles of spiral shocks, magnetorotational instability (MRI), and the accretion stream on disk structure and evolution. In preparation for these global models, we test the effects of numerical diffusion relevant to studies of accretion disks. We perform one- and two-dimensional simulations of a dense cold Keplerian ring surrounded by a hot hydrostatic atmosphere, varying the Riemann solver, resolution, and the reconstruction method used. Finding HLLC/Roe Riemann solver and PLM reconstruction to be the best fit for our needs, we build our global models of CV disks. We include a simple treatment of gas thermodynamics designed to approximate conditions typical of dwarf nova outbursts, with orbital Mach numbers at the inner edge of the disk M_in of 5 and 10. We find mass accretion rates in our global models to vary considerably on all time scales, with only the Mach 5 model reaching a clear quasi-stationary state. For Mach 10, the model undergoes an outside-in magnetically-driven accretion event occurring on a time scale of ~10 orbital periods of the binary. Both models exhibit spiral shocks inclined with respect to the binary plane, with their position and inclination changing rapidly. However, the time-averaged location of these shocks in the equatorial plane is well-fit by simple linear models. MRI turbulence in the disk generates toroidal magnetic field patterns (butterfly diagrams) that are in some cases irregular, perhaps due to interaction with spiral structure. While many of our results are in good agreement with local studies, we find some features (most notably those related to spiral shocks) can only be captured in global models such as studied here. Thus, while global studies remain computationally expensive, we find them essential (along with more sophisticated treatment of radiation transport and disk thermodynamics) for furthering our understanding of accretion in binary systems. Finally, we discuss future improvements to our framework including the use of orbital advection, where early tests indicate 50-100% improvement in code performance. Advisors/Committee Members: Stone, James M (advisor).

Subjects/Keywords: cataclysmic variable stars; magnetohydrodynamical simulations; semi-detached binary stars; stellar accretion disks

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APA (6^th Edition):

Pjanka, P. (2020). Cataclysmic Variables in MHD . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01v405sd437

Chicago Manual of Style (16^th Edition):

Pjanka, Patryk. “Cataclysmic Variables in MHD .” 2020. Doctoral Dissertation, Princeton University. Accessed March 07, 2021. http://arks.princeton.edu/ark:/88435/dsp01v405sd437.

MLA Handbook (7^th Edition):

Pjanka, Patryk. “Cataclysmic Variables in MHD .” 2020. Web. 07 Mar 2021.

Vancouver:

Pjanka P. Cataclysmic Variables in MHD . [Internet] [Doctoral dissertation]. Princeton University; 2020. [cited 2021 Mar 07]. Available from: http://arks.princeton.edu/ark:/88435/dsp01v405sd437.

Council of Science Editors:

Pjanka P. Cataclysmic Variables in MHD . [Doctoral Dissertation]. Princeton University; 2020. Available from: http://arks.princeton.edu/ark:/88435/dsp01v405sd437

Vanderbilt University

14. Mack, Claude Ernest III. Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars.

Degree: PhD, Physics, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/15345

► In the era of large-scale surveys for exoplanets, it is important to be aware of the pernicious false positives that can contaminate survey samples. In… (more)

Subjects/Keywords: exoplanets; binary stars; radial velocity; chemical abundances; spectroscopy; spectral analysis; spectroscopic binary; condensation temperature

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APA (6^th Edition):

Mack, C. E. I. (2014). Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15345

Chicago Manual of Style (16^th Edition):

Mack, Claude Ernest III. “Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed March 07, 2021. http://hdl.handle.net/1803/15345.

MLA Handbook (7^th Edition):

Mack, Claude Ernest III. “Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars.” 2014. Web. 07 Mar 2021.

Vancouver:

Mack CEI. Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1803/15345.

Council of Science Editors:

Mack CEI. Large Radial Velocity Searches and Chemical Abundance Studies of Exoplanet-Hosting Stars. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/15345

Penn State University

15. Johnson-McDaniel, Nathan Kieran. Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics .

Degree: 2011, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/12222

► In this dissertation, we present various theoretical investigations of sources of gravitational waves, relevant to interpreting the data from current and planned gravitational wave… (more)

▼ In this dissertation, we present various theoretical investigations of sources of gravitational waves, relevant to interpreting the data from current and planned gravitational wave detectors; an <i>idée fixe</i> is the deformation of compact objects. We begin in the strong field, vacuum regime, with a construction of initial data for the numerical simulation of black hole binaries (specializing to the case of nonspinning holes in a quasicircular orbit). The data we construct contain more of the binary's expected physics than any other current data set. In particular, they contain both the binary's outgoing radiation and the expected tidal deformations of the holes. Such improved initial data will likely be necessary for simulations to achieve the accuracy required to supply advanced gravitational wave detectors with templates for parameter estimation. We end in the weak field, hydrodynamic regime with a calculation of the expected accuracy with which one can combine standard electromagnetic and gravitational wave observations of white dwarf binaries to measure the masses of the binary's components. In particular, we show that this measurement will not be contaminated by finite size effects for realistic sources observed by LISA, though such effects could be important for exceptional sources and/or advanced mHz gravitational wave detectors. In the middle, we make a detour into the messy and poorly constrained realm of the physics of neutron star interiors, calculating the shear modulus of hadron–quark mixed phase in hybrid stars. Here we include a rough treatment of charge screening, dimensional continuation of the lattice, and the contributions from changing the cell volume when shearing lower-dimensional lattices. We find that the last of these contributions is necessary to stabilize the lattice for those dimensions, where it makes a considerable contribution to the shear modulus. We then move back to sounder theoretical footing in making a general relativistic calculation of the maximum elastic quadrupole deformation that could be sustained by a star with a known shear modulus and breaking strain (provided by, e.g., the hadron–quark mixed phase in the core, or the more standard lattice of nuclei in the crust). We find that the standard Newtonian calculation considerably overestimates the quadrupole, particularly for massive, compact stars. We also present the dimensionally continued Poisson summation formula we discovered while performing the shear modulus calculation, and thought interesting enough to prove rigorously. Our method of proof also provides a new way of proving other (Voronoi) summation formulae obtained from functions satisfying modular transformations, and allows one to relax certain of the standard hypotheses. Advisors/Committee Members: Benjamin J Owen, Dissertation Advisor/Co-Advisor, Benjamin J Owen, Committee Chair/Co-Chair, Martin Bojowald, Committee Member, Irina Mocioiu, Committee Member, Steinn Sigur&Eth;Sson, Committee Member.

Subjects/Keywords: summation formulae; binary white dwarfs; neutron stars; relativistic astrophysics; binary black holes; gravitational waves

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APA (6^th Edition):

Johnson-McDaniel, N. K. (2011). Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics . (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/12222

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Johnson-McDaniel, Nathan Kieran. “Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics .” 2011. Thesis, Penn State University. Accessed March 07, 2021. https://submit-etda.libraries.psu.edu/catalog/12222.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Johnson-McDaniel, Nathan Kieran. “Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics .” 2011. Web. 07 Mar 2021.

Vancouver:

Johnson-McDaniel NK. Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics . [Internet] [Thesis]. Penn State University; 2011. [cited 2021 Mar 07]. Available from: https://submit-etda.libraries.psu.edu/catalog/12222.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Johnson-McDaniel NK. Gravitational waves and the deformation of compact objects: Topics in relativistic astrophysics . [Thesis]. Penn State University; 2011. Available from: https://submit-etda.libraries.psu.edu/catalog/12222

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Vanderbilt University

16. Dhital, Saurav. Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters.

Degree: PhD, Physics, 2012, Vanderbilt University

URL: http://hdl.handle.net/1803/10988

► I identified and used a large catalog of ultra-wide binaries to investigate observationally two related questions in low-mass star astrophysics: (1) What is the frequency… (more)

▼ I identified and used a large catalog of ultra-wide binaries to investigate observationally two related questions in low-mass star astrophysics: (1) What is the frequency and distribution of ultra-wide binary systems, and what can they tell us about formation processes? and (2) How can we use wide binaries as coeval laboratories to measure the fundamental parameters—specifically, metallicity and age—of low-mass stars? The Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES) catalog of ultra-wide (10^3-10⁵.5) AU), low-mass (K5–M7) common proper motion binaries is comprised of 1342 disk dwarf, subdwarf, and white dwarf–red dwarf systems, making it the largest catalog of wide binaries. A Galactic model, based on empirical stellar number density and space velocity distributions, was constructed to select only bona fide pairs with probability of chance alignment <5%, making SLoWPoKES an efficient sample for followup observations. Our findings suggest that the SLoWPoKES binaries could have formed via a combination of two modes of wide binary formation – dynamical widening and cluster dissipation. Comparison with dynamical dissipation timescales of wide binaries and the high incidence of hierarchical multiples suggest the widest systems could be the result of dynamical widening. On the other hand, the distribution of physical separations of wide binary and the tight binary (when present) is similar to results from numerical simulations of cluster dissipation. From spectroscopic followup of SLoWPoKES pairs, we confirmed that the ζ_(TiO/CaH) index traces iso-metallicity loci for most of our sample of M dwarfs. However, we found a small systematic bias in ζ_(TiO/CaH), especially for early-type M dwarfs. We used our sample to recalibrate the definition of ζ_(TiO/CaH). While representing a small change in the definition, the new ζ_(TiO/CaH) is a significantly better predictor of iso-metallicity for early-type M dwarfs. Advisors/Committee Members: Andrew A. West (committee member), Sydney A. Barnes (committee member), Kelly Holley-Bockelmann (committee member), Thomas J. Weiler (committee member), David A. Weintraub (committee member), Keivan G. Stassun (Committee Chair).

Subjects/Keywords: star formation; metallicity; M dwarfs; low-mass stars; brown dwarfs; binary stars; astrophysics; astronomy; stars; subdwarfs

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APA (6^th Edition):

Dhital, S. (2012). Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10988

Chicago Manual of Style (16^th Edition):

Dhital, Saurav. “Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed March 07, 2021. http://hdl.handle.net/1803/10988.

MLA Handbook (7^th Edition):

Dhital, Saurav. “Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters.” 2012. Web. 07 Mar 2021.

Vancouver:

Dhital S. Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1803/10988.

Council of Science Editors:

Dhital S. Ultra-wide, Low-mass Binaries: Constraints on Binary Formation Theory and Calibration of Fundamental Stellar Parameters. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/10988

17. Fullard, Andrew G. A Spectropolarimetric Study of Southern WR + O Binaries.

Degree: PhD, Physics and Astronomy, 2020, U of Denver

URL: https://digitalcommons.du.edu/etd/1762

► 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… (more)

▼ 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 in binary systems may provide sufficient angular momentum to create such progenitors. Angular momentum (and therefore rotation) tends to create aspherical structures in astronomical objects (e.g. Be star disks, T Tauri jets caused by decretion and accretion respectively) that can be investigated using linear polarimetry, even for unresolved sources. I have investigated WR stars in detail to determine the geometric structure of their winds using spectropolarimetry. I began by using archival broadband polarimetric data to search for intrinsic polarization in a sample of more than 40 single and binary WR stars, finding that 12 of the stars exhibit intrinsic continuum polarization or line polarization effects that indicate aspherical or non-uniform winds. In the later stages of the project, I used the Southern African Large Telescope (SALT) to obtain time-dependent spectropolarimetric observations of 10 of the stars in that sample, along with 8 additional targets. These targets are all WR + O binary systems, whose complex winds are best observed over time with spectropolarimetry to determine the geometry of the wind across different emission lines and the continuum. I investigated two stars in the sample, WR 42 and WR 79, and found that they exhibit classic continuum polarization signatures of binary orbits, as well as intriguing orbital line polarization effects. I compared the line polarization behaviour with the predictions of existing spectrally-derived models of the systems to obtain new information about the structure of the colliding wind regions. Finally, I have modified an existing 3-D Monte Carlo radiative transfer code to include an additional source of photons that represents a companion star. This allows the code to treat the asymmetric structures seen in massive binary systems. I used this updated code to simulate the well-observed WR + O system V444 Cygni. I created a set of emission regions to simulate line emission from both the WR wind and wind-wind collision regions, finding that the wind-wind collision creates very strong polarimetric signals that appear similar to those in other systems in my SALT sample. The results shed new light on the relationships among WR + O binaries and yield clues to their subsequent evolution and potential roles as SN and GRB progenitors. Advisors/Committee Members: Jennifer L. Hoffman, Toshiya Ueta, Robert Stencel.

Subjects/Keywords: Binary stars; Massive stars; Polarization; Radiative transfer; Wolf-rayet; Astrophysics and Astronomy; Stars, Interstellar Medium and the Galaxy

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APA (6^th Edition):

Fullard, A. G. (2020). A Spectropolarimetric Study of Southern WR + O Binaries. (Doctoral Dissertation). U of Denver. Retrieved from https://digitalcommons.du.edu/etd/1762

Chicago Manual of Style (16^th Edition):

Fullard, Andrew G. “A Spectropolarimetric Study of Southern WR + O Binaries.” 2020. Doctoral Dissertation, U of Denver. Accessed March 07, 2021. https://digitalcommons.du.edu/etd/1762.

MLA Handbook (7^th Edition):

Fullard, Andrew G. “A Spectropolarimetric Study of Southern WR + O Binaries.” 2020. Web. 07 Mar 2021.

Vancouver:

Fullard AG. A Spectropolarimetric Study of Southern WR + O Binaries. [Internet] [Doctoral dissertation]. U of Denver; 2020. [cited 2021 Mar 07]. Available from: https://digitalcommons.du.edu/etd/1762.

Council of Science Editors:

Fullard AG. A Spectropolarimetric Study of Southern WR + O Binaries. [Doctoral Dissertation]. U of Denver; 2020. Available from: https://digitalcommons.du.edu/etd/1762

18. Saulo Carneiro Maciel. Sistemas binários eclipsantes na missão CoRot.

Degree: 2011, Universidade Federal do Rio Grande do Norte

URL: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=4754

► Sessenta e cinco sistemas binários eclipsantes, identificados nos objetivos da missão espacial CoRoT, foram selecionados para a análise. Destes, cinquenta e nove curvas de luz… (more)

Subjects/Keywords: FISICA; Estrelas corot; Binárias eclipsantes; Corot Stars; Eclipsing Binary

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APA (6^th Edition):

Maciel, S. C. (2011). Sistemas binários eclipsantes na missão CoRot. (Thesis). Universidade Federal do Rio Grande do Norte. Retrieved from http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=4754

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Maciel, Saulo Carneiro. “Sistemas binários eclipsantes na missão CoRot.” 2011. Thesis, Universidade Federal do Rio Grande do Norte. Accessed March 07, 2021. http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=4754.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Maciel, Saulo Carneiro. “Sistemas binários eclipsantes na missão CoRot.” 2011. Web. 07 Mar 2021.

Vancouver:

Maciel SC. Sistemas binários eclipsantes na missão CoRot. [Internet] [Thesis]. Universidade Federal do Rio Grande do Norte; 2011. [cited 2021 Mar 07]. Available from: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=4754.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Maciel SC. Sistemas binários eclipsantes na missão CoRot. [Thesis]. Universidade Federal do Rio Grande do Norte; 2011. Available from: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=4754

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Michigan

19. Spencer, Meghin. Binary Stars in Dwarf Spheroidal Galaxies.

Degree: PhD, Astronomy and Astrophysics, 2017, University of Michigan

URL: http://hdl.handle.net/2027.42/140878

► Dwarf spheroidal galaxies (dSphs) are the smallest, most numerous, and among the oldest galaxies in the Universe. Since their discovery in the 1930's, dSphs have… (more)

▼ Dwarf spheroidal galaxies (dSphs) are the smallest, most numerous, and among the oldest galaxies in the Universe. Since their discovery in the 1930's, dSphs have provided insights into ancient stellar populations, galaxy formation, and early Universe star formation. Beginning in the 1980's, spectroscopy revealed anomalous stellar kinematics within dSph galaxies, which is typically interpreted as considerable amounts of dark matter (DM) existing in these systems. One kinematic effect that could mimic DM arises from the orbital motions of binary stars; however, subsequent work found that binaries alone could not account for the anomalous kinematics within the larger dSph galaxies. The recent discovery of a new class of dSphs called "ultra-faints" has reignited the issues of binaries due to the intrinsically low velocity dispersions in these systems. Motivated by the need to better understand the extent of binary contamination in ultra-faints, this dissertation draws upon both recent and archival data in brighter dSphs to determine updated kinematic properties and to provide a fresh look at the binary fraction within dSphs. The spectroscopic data used in this dissertation comes from many different telescopes and instruments, spans 2-3 decades in time, and concerns three dSphs: Leo II, Draco, and Ursa Minor. For Leo II, our analysis included a new study of the galaxy's internal kinematics, finding among other results, (a) the V-band mass-to-light ratio is 15.2+-5.5, (b) no signs of internal rotation, and (c) suggestive evidence of kinematic substructure related to metallicity. The full kinematic datasets for all three dwarfs were used to characterize the likely binary fraction of each galaxy under the assumption that velocity fluctuations for individual stars with multiple observations were due to binaries. The process we followed was to first generate Monte Carlo simulations of the observations, whereby binary fraction was varied. Then we performed a Bayesian analysis that compared the simulations with the data to discern the most likely binary fraction in each dSph. We explored various mass ratio, eccentricity, and period distributions throughout the simulations. We also applied our method to preexisting data in Carina, Fornax, Sculptor, and Sextans to yield a homogeneous measurement of binary fraction in seven dwarfs – the largest sample to date. The probability that the binary fraction is the same (i.e., exists within a range of fractions spanning 20%) amongst these dwarfs is <1%. We generally found no significant correlations between binary fraction and other galactic properties, though we cannot rule out a weak dependence with star-formation history. Given the variability of binary fraction that we inferred between galaxies, we modeled the effects of binaries on the global kinematics of mock dwarf galaxies as a function of binary fraction. We simulated different intrinsic dispersions for dwarfs, sample sizes, number of observations, and size of velocity errors. Unless the binary fraction is low (<10%), binaries… Advisors/Committee Members: Mateo, Mario L (committee member), Huterer, Dragan (committee member), Bell, Eric F (committee member), Loebman, Sarah R (committee member), Valluri, Monica (committee member).

Subjects/Keywords: Dwarf Galaxies; Binary Stars; Dark Matter; Astronomy; Science

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APA (6^th Edition):

Spencer, M. (2017). Binary Stars in Dwarf Spheroidal Galaxies. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/140878

Chicago Manual of Style (16^th Edition):

Spencer, Meghin. “Binary Stars in Dwarf Spheroidal Galaxies.” 2017. Doctoral Dissertation, University of Michigan. Accessed March 07, 2021. http://hdl.handle.net/2027.42/140878.

MLA Handbook (7^th Edition):

Spencer, Meghin. “Binary Stars in Dwarf Spheroidal Galaxies.” 2017. Web. 07 Mar 2021.

Vancouver:

Spencer M. Binary Stars in Dwarf Spheroidal Galaxies. [Internet] [Doctoral dissertation]. University of Michigan; 2017. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2027.42/140878.

Council of Science Editors:

Spencer M. Binary Stars in Dwarf Spheroidal Galaxies. [Doctoral Dissertation]. University of Michigan; 2017. Available from: http://hdl.handle.net/2027.42/140878

20. Kostov, Veselin. Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission.

Degree: 2014, Johns Hopkins University

URL: http://jhir.library.jhu.edu/handle/1774.2/37188

► Planets with two suns have long fascinated our imagination yet it was only recently that astronomers were able to provide direct evidence of their existence.… (more)

▼ Planets with two suns have long fascinated our imagination yet it was only recently that astronomers were able to provide direct evidence of their existence. Several candidates have been proposed since 2003, based on measured timing variations in binary stellar systems, but it was not until 2011 and the launch of NASA’s Kepler mission that circumbinary planets were unambiguously detected through their transits. At the time of writing, the peerless-quality data from Kepler has enabled the confirmation of eight planets orbiting both members of seven gravitationally bound, eclipsing binaries (one of the systems has two circumbinary planets). This thesis presents our contribution to the field in terms of discovery and characterization of three of these transiting circumbinary planetary systems, specifically Kepler-47, Kepler-64, Kepler-413. As predicted by theoretical models, the planets we discovered are smaller than Jupiter, have orbits close to the limit for dynamical stability, and are nearly co-planar to their host binaries (although the circumbinary system Kepler-413 is sufficiently misaligned that, due to fast orbital precession, the planet does not transit at every inferior conjunction). The results of our work deliver important insight into the nature of this remarkable new class of objects, and provide deeper understanding of a) the type of binary stars that can support circumbinary planets; b) the orbital and physical properties of these fascinating systems (e.g. sizes, masses, orbital eccentricities, inclinations, precession rates); and c) planet formation and evolution in multiple stellar systems. Adding new members to the still small family of circumbinary planets has direct relevance for estimating the occurrence frequency of planets around binary stars in particular, and the Galactic planetary census in general, and for the extension of the concept of habitability to binary stellar systems. Here we describe the unique observational signatures of transiting circumbinary planets, the detection method and analysis tools we developed to find and characterize these systems, and the theoretical implications of our discoveries. Specifically, we present the custom-built algorithm we invented to search for individual transit signatures in a light curve. We applied the algorithm to the light curves of ~800 eclipsing binaries from Kepler, and discovered the aperiodic planetary transits in the three circumbinary systems mentioned above. To capitalize on these transits, we developed an analytical model that uses their measured depths and durations to constrain the properties of the host binary star. In addition, we present our ground-based spectroscopic and photometric observations that allowed us to measure the radial velocities of the circumbinary host stars and to constrain photometric contamination from unresolved sources. Finally, we discuss the photometric-dynamic model we developed and applied for the complete characterization of the transiting circumbinary systems Kepler-64 and Kepler-413. Advisors/Committee Members: McCullough, Peter (advisor).

Subjects/Keywords: exoplanets; binary stars

…Binary Stars . . . . . . 1.5 Circumbinary Planets… …x28;to a few degrees) for binary stars with sub-AU semi-major axes due to disk-binary… …for the extension of the concept of habitability to binary stars. More specifically, as we… …and masses of the stellar components of the host binary stars. The measurements for the M… …For a given binary system, the minimum allowed distance from the two stars beyond which a…

11 more images…

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APA (6^th Edition):

Kostov, V. (2014). Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/37188

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kostov, Veselin. “Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission.” 2014. Thesis, Johns Hopkins University. Accessed March 07, 2021. http://jhir.library.jhu.edu/handle/1774.2/37188.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kostov, Veselin. “Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission.” 2014. Web. 07 Mar 2021.

Vancouver:

Kostov V. Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission. [Internet] [Thesis]. Johns Hopkins University; 2014. [cited 2021 Mar 07]. Available from: http://jhir.library.jhu.edu/handle/1774.2/37188.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kostov V. Discovery and characterization of transiting circumbinary planets from NASA's Kepler mission. [Thesis]. Johns Hopkins University; 2014. Available from: http://jhir.library.jhu.edu/handle/1774.2/37188

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Washington

21. Fleming, David Paul. Inferring the Evolutionary Histories of Stars and Their Planets.

Degree: PhD, 2020, University of Washington

URL: http://hdl.handle.net/1773/45818

► Modern surveys like NASA’s Kepler mission have collected a wealth of data in the search for Earth-like exoplanets. This vast quantity of data has enabled… (more)

▼ Modern surveys like NASA’s Kepler mission have collected a wealth of data in the search for Earth-like exoplanets. This vast quantity of data has enabled novel statistical investigations of the physical processes that shape the observed populations of stars and their planets. Theoretical mod- els are required to explain how and why planetary systems evolved to their present state because models produce hypotheses for how physical mechanisms operate that can be directly tested by observational data. One can therefore compare model predictions with observed data and its un- certainties, a process mathematically formalized by Bayesian inference, to infer and understand the long-term evolution of planetary systems. In this dissertation, I developed theoretical models to understand the long-term evolution of single and binary stars. My work focused on simulating the dynamical evolution of stellar systems and explored what impact this evolution had on the planetary system architecture and planetary habitability. Through an ensemble of N-body simulations, I explored how resonant gravitational torques in young circumbinary systems impact the orbital evolution of the central binary and its external circumbinary protoplanetary disk. I demonstrated that binaries with eccentric orbits strongly coupled to the disk and excited eccentricity growth for both the binary orbit and the disk. I found that binaries on nearly circular orbits, however, weakly coupled to the disk and only caused eccentricity growth within the disk. I continued my work on circumbinary systems to develop a model for the early coupled stellar-tidal evolution of planet-hosting binary stars. I showed how the early tidally-driven expansion of short-period binary orbits can destabilize close-in circumbinary planets thereby explaining the lack of observed transiting circumbinary planets in the Kepler field. I extended my model for the coupled stellar-tidal evolution of binary stars and applied it to Kepler binaries to probe how stellar evolution, tidal torques, and magnetic braking can shape the rotation period evolution of low-mass binary stars. I showed that my model naturally reproduced the population of short-period subsynchronous Kepler eclipsing binaries discovered by Lurie et al. (2017). Moreover, I explained how tidal torques can often force the rotation period evolution of stellar binaries to depart from the long-term magnetic braking-driven spin down experienced by single stars revealing that the stellar rotation period is not always a valid proxy for age, i.e. gyrochronology can underestimate ages by up to 300%. I combined my models for stellar evolution with Bayesian inference via Markov chain Monte Carlo sampling to put probabilistic constraints on the X-ray and ultraviolet (XUV) emission history of TRAPPIST-1 and understand the evolving high-energy radiation environment experienced by its planets. I inferred that there is a ∼40% chance that TRAPPIST-1 is still in the saturated phase today, suggesting that it has maintained LXUV /Lbol ≈ 10−3 for… Advisors/Committee Members: Barnes, Rory (advisor).

Subjects/Keywords: Binary stars; Dynamics; Exoplanets; Machine Learning; Astronomy; Astronomy

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Fleming, D. P. (2020). Inferring the Evolutionary Histories of Stars and Their Planets. (Doctoral Dissertation). University of Washington. Retrieved from http://hdl.handle.net/1773/45818

Chicago Manual of Style (16^th Edition):

Fleming, David Paul. “Inferring the Evolutionary Histories of Stars and Their Planets.” 2020. Doctoral Dissertation, University of Washington. Accessed March 07, 2021. http://hdl.handle.net/1773/45818.

MLA Handbook (7^th Edition):

Fleming, David Paul. “Inferring the Evolutionary Histories of Stars and Their Planets.” 2020. Web. 07 Mar 2021.

Vancouver:

Fleming DP. Inferring the Evolutionary Histories of Stars and Their Planets. [Internet] [Doctoral dissertation]. University of Washington; 2020. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1773/45818.

Council of Science Editors:

Fleming DP. Inferring the Evolutionary Histories of Stars and Their Planets. [Doctoral Dissertation]. University of Washington; 2020. Available from: http://hdl.handle.net/1773/45818

22. Tyndall, Amy. A Study of Planetary Nebulae Possessing Binary Central Stars.

Degree: 2014, University of Manchester

URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:222479

► In this thesis, detailed studies of three different types of binary central stars withinplanetary nebulae (bCSPNe) are presented, with the aim of investigating the effectssuch… (more)

▼ In this thesis, detailed studies of three different types of binary central stars withinplanetary nebulae (bCSPNe) are presented, with the aim of investigating the effectssuch a range of binary systems has on the morphology and kinematics of the surroundingnebulae, as well as discussing what the implication is for the interaction betweenthe stars themselves. A close binary, an intermediate period binary, and a compactbinary system are examined.The close binary PN HaTr 4 is the first system to be studied via detailed spatiokinematicalanalysis and modelling, and it is one of few known to contain a postcommonenvelope (CE) central star system. CE evolution is believed to play an importantrole in the shaping of PNe, but the exact nature of this role is yet to be understood.High spatial and spectral resolution spectroscopy is presented alongside deep narrowbandimagery to derive the three-dimensional morphology of HaTr 4. The nebula isfound to display an extended ovoid morphology with an enhanced equatorial regionconsistent with a toroidal waist - a feature believed to be typical amongst PNe withpost-CE central stars. The nebular symmetry axis is found to lie perpendicular to theorbital plane of the central binary, concordant with the idea that the formation andevolution of HaTr 4 has been strongly influenced by its central binary.Next, PN LoTr 1 is studied using a combination of spectra and photometry, andis thought to contain an intermediate-period binary central star system (P = 100–1500d). Here, we confirm the binary nature of the central star of LoTr 1, consisting of aK1 III star and a hot white dwarf (WD). The nebula of LoTr 1 presents a very differentmorphology than that of other seemingly similar bCSPNe possessing barium stars,A70 and WeBo 1 (included in this study for direct comparison), which may be anindication of a difference in their mass-transfer episodes. There is no evidence ofbarium enhancement in the K1 III companion, but it is shown to have a rotation periodof 6.4 d which is most likely a sign of mass accretion. Such a system represents arare opportunity to further the investigation into the formation of barium stars andintermediate period, post-asymptotic giant branch (AGB) systems.Finally, the first analysis of an object from the new POPIPlaN catalogue of PNe ispresented. Photometry of the central star system of PN G033.8+01.5 showed it to bea compact binary of P = 0.1268 d, consisting of a cool M2 V main sequence star anda hot WD surrounded by a very asymmetric PN. The very short orbital period leadsto the possibility of PN G033.8+01.5 being a cataclysmic variable candidate, which inturn leads to the question of whether the visible nebulous material is that of a true PNor if it is the remnant of an outburst. Advisors/Committee Members: Lloyd, Myfanwy.

Subjects/Keywords: Planetary nebulae; Binary stars

…CONTENTS 8 A Study on PN Possessing Binary Central Stars List of Figures 1.1… …Binary Central Stars LIST OF FIGURES 5.2 Original Hα and red images of PN G033.8+01.5 from… …181 Amy A. Tyndall 11 LIST OF FIGURES 12 A Study on PN Possessing Binary Central Stars… …List of Tables 1.1 PNe with known close binary central stars… …PN Possessing Binary Central Stars Abstract Thesis submitted by Amy A. Tyndall for the…

8 more images…

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APA (6^th Edition):

Tyndall, A. (2014). A Study of Planetary Nebulae Possessing Binary Central Stars. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:222479

Chicago Manual of Style (16^th Edition):

Tyndall, Amy. “A Study of Planetary Nebulae Possessing Binary Central Stars.” 2014. Doctoral Dissertation, University of Manchester. Accessed March 07, 2021. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:222479.

MLA Handbook (7^th Edition):

Tyndall, Amy. “A Study of Planetary Nebulae Possessing Binary Central Stars.” 2014. Web. 07 Mar 2021.

Vancouver:

Tyndall A. A Study of Planetary Nebulae Possessing Binary Central Stars. [Internet] [Doctoral dissertation]. University of Manchester; 2014. [cited 2021 Mar 07]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:222479.

Council of Science Editors:

Tyndall A. A Study of Planetary Nebulae Possessing Binary Central Stars. [Doctoral Dissertation]. University of Manchester; 2014. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:222479

Boston University

23. Morgan, Dylan Parker. The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions.

Degree: PhD, Astronomy, 2017, Boston University

URL: http://hdl.handle.net/2144/20874

► I present a study of close white dwarf (WD) and M dwarf (dM) binary systems (WD+dM) to examine the effects that close companions have on… (more)

▼ I present a study of close white dwarf (WD) and M dwarf (dM) binary systems (WD+dM) to examine the effects that close companions have on the magnetic field generation in dMs. Using the Sloan Digital Sky Survey (SDSS) Data Release 8 spectroscopic database, I construct a sample of 1756 WD+dM high-quality pairs. I show that high-mass dMs (≤M4) in close binary systems are more likely to be magnetically active (as measured by Hα emission) and are able to remain active longer than field dMs. At lower masses (≥M5), where dMs become fully convective, the activity fraction and activity lifetimes of WD+dM binary systems become more comparable to those of the field dMs. The implications of having a close binary companion may include, increased stellar rotation through disk disruption, tidal effects, and/or angular momentum exchange. Thus, the similarity in activity between late-type field dMs and late-type dMs with close companions is likely due to the mechanism generating magnetic fields being less sensitive to the effects caused by a close companion; namely, increased stellar rotation. Using a subset of 181 close WD+dM pairs, matched to the time-domain SDSS Stripe 82 catalog, I show that enhanced magnetic activity extends to the flaring behavior of dMs in close binaries. Specifically, early spectral type dMs (M0-M1), in close WD+dM pairs, are two orders of magnitude more likely to flare than field dMs, whereas mid-type dMs (M2-M3) and late-type dMs (M4-M6) flare as frequently or less than the mid- to late-type field dM sample. To test whether the presence of a close companion leads to star-star interactions, I search for correlations between the WD occultations and flares from the dM member in KOI-256, an eclipsing WD+dM system from Kepler I find no correlations between the flaring activity of the dM and the WD occultations, indicating the there are no obvious signs of star-star interactions at work. In addition, the dM member of KOI-256 flares more than any other dM observed by Kepler and shows evidence for solar-like magnetic activity cycles, a feature not seen in many dMs to date.

Subjects/Keywords: Astronomy; Binary stars; M dwarfs; Magnetic fields; White dwarfs

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APA (6^th Edition):

Morgan, D. P. (2017). The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions. (Doctoral Dissertation). Boston University. Retrieved from http://hdl.handle.net/2144/20874

Chicago Manual of Style (16^th Edition):

Morgan, Dylan Parker. “The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions.” 2017. Doctoral Dissertation, Boston University. Accessed March 07, 2021. http://hdl.handle.net/2144/20874.

MLA Handbook (7^th Edition):

Morgan, Dylan Parker. “The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions.” 2017. Web. 07 Mar 2021.

Vancouver:

Morgan DP. The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions. [Internet] [Doctoral dissertation]. Boston University; 2017. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2144/20874.

Council of Science Editors:

Morgan DP. The effects of close binaries on the magnetic activity of M dwarfs as probed using close white dwarf companions. [Doctoral Dissertation]. Boston University; 2017. Available from: http://hdl.handle.net/2144/20874

University of Exeter

24. Cardoso, Catia Vanessa Varejao. Observational properties of brown dwarfs : the low-mass end of the mass function.

Degree: PhD, 2012, University of Exeter

URL: https://ore.exeter.ac.uk/repository/handle/10036/3592 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552963

► Brown dwarfs are objects with sub-stellar masses that are unable to sustain hydrogen burning, cooling down through out their lifetimes. This thesis presents two projects,… (more)

▼ Brown dwarfs are objects with sub-stellar masses that are unable to sustain hydrogen burning, cooling down through out their lifetimes. This thesis presents two projects, the study of the IMF of the double cluster, h & χ Persei, and the determination of the dynamical masses of the brown dwarf binary, ε Indi Ba, Bb. The study of a cluster’s population distribution gives us the opportunity to study a statistically meaningful population of objects over a wide range of masses (from massive stars to brown dwarfs), with a similar age and chemical composition providing formation and dynamical evolution constraints. h & χ Persei is the largest double cluster known in our galaxy. Using optical and infrared photometric data we have produced the deepest mass function for the system. A study of the radial distribution shows evidence of mass segregation while the mass function shows that these clusters may be suffering from accelerated dynamical evolution due to their interaction, triggering the ejection of brown dwarfs. The physical parameterization of brown dwarfs is reliant on the use of interior and atmospheric models. The study of brown dwarf binaries can provide crucial model independent measurements, especially masses. ε Indi Ba, Bb (spectral types T1 and T6) is the closest known brown dwarf binary to Earth. The brown dwarf binary itself orbits a main sequence star allowing us to constrain the distance, metallicity and age of the system making it possible to break the sub-stellar mass-age-luminosity degeneracy. The relative motion of the brown dwarf binary has been studied with precision astrometry from infrared AO data, allowing the determination of the system mass, 121.16 ± 0.17 ± 1.08 MJup . The individual masses of the binary components were derived from the absolute movement of the binary to be MBa = 68.04±0.94 MJup and MBb = 53.12±0.32 MJup. We concluded that the isochronally-derived masses were underestimating the system mass by ∼ 60%, due to the likely underestimation of the age of the system. The evolutionary models are consistent with the parameters measured observationally if the system has an age ∼ 4 Gyr.

Subjects/Keywords: 523.88; Star Formation; Brown Dwarfs; Binary and multiple stars

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APA (6^th Edition):

Cardoso, C. V. V. (2012). Observational properties of brown dwarfs : the low-mass end of the mass function. (Doctoral Dissertation). University of Exeter. Retrieved from https://ore.exeter.ac.uk/repository/handle/10036/3592 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552963

Chicago Manual of Style (16^th Edition):

Cardoso, Catia Vanessa Varejao. “Observational properties of brown dwarfs : the low-mass end of the mass function.” 2012. Doctoral Dissertation, University of Exeter. Accessed March 07, 2021. https://ore.exeter.ac.uk/repository/handle/10036/3592 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552963.

MLA Handbook (7^th Edition):

Cardoso, Catia Vanessa Varejao. “Observational properties of brown dwarfs : the low-mass end of the mass function.” 2012. Web. 07 Mar 2021.

Vancouver:

Cardoso CVV. Observational properties of brown dwarfs : the low-mass end of the mass function. [Internet] [Doctoral dissertation]. University of Exeter; 2012. [cited 2021 Mar 07]. Available from: https://ore.exeter.ac.uk/repository/handle/10036/3592 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552963.

Council of Science Editors:

Cardoso CVV. Observational properties of brown dwarfs : the low-mass end of the mass function. [Doctoral Dissertation]. University of Exeter; 2012. Available from: https://ore.exeter.ac.uk/repository/handle/10036/3592 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552963

25. Davey, Stephen. Irradiation of the secondary star in cataclysmic variable stars.

Degree: PhD, 1994, University of Sussex

URL: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386388

Subjects/Keywords: 523.01; Binary stars; Stellar imaging

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APA (6^th Edition):

Davey, S. (1994). Irradiation of the secondary star in cataclysmic variable stars. (Doctoral Dissertation). University of Sussex. Retrieved from https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386388

Chicago Manual of Style (16^th Edition):

Davey, Stephen. “Irradiation of the secondary star in cataclysmic variable stars.” 1994. Doctoral Dissertation, University of Sussex. Accessed March 07, 2021. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386388.

MLA Handbook (7^th Edition):

Davey, Stephen. “Irradiation of the secondary star in cataclysmic variable stars.” 1994. Web. 07 Mar 2021.

Vancouver:

Davey S. Irradiation of the secondary star in cataclysmic variable stars. [Internet] [Doctoral dissertation]. University of Sussex; 1994. [cited 2021 Mar 07]. Available from: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386388.

Council of Science Editors:

Davey S. Irradiation of the secondary star in cataclysmic variable stars. [Doctoral Dissertation]. University of Sussex; 1994. Available from: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386388

University of Manchester

26. Jones, David. The influence of central star binarity on the morphologies of planetary nebulae.

Degree: PhD, 2011, University of Manchester

URL: https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-central-star-binarity-on-the-morphologies-of-planetary-nebulae(0d5924db-e0fb-4ebd-bacc-38e8196efb5e).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542694

► Central star binarity is often invoked as the main driver behind the shaping of aspherical planetary nebulae, however observational support for this hypothesis is lacking.… (more)

▼ Central star binarity is often invoked as the main driver behind the shaping of aspherical planetary nebulae, however observational support for this hypothesis is lacking. This work presented in this thesis attempts to observationally test this theory by investigating the relationship between central star binarity and nebular morphology for several planetary nebulae. The discovery of six new binary central star systems is also reported. A detailed spatio-kinematical analysis of Abell 41 was performed, showing the nebula to have a bipolar morphology waisted by a toroidal structure, the symmetry axis of which is found to be perpendicular to the plane of the central binary. This alignment is exactly as predicted, indicating that the central binary, MT Ser, has played a significant role in shaping Abell 41. This is only the second planetary nebulae to have had this link, between binary and nebular inclination, explicitly shown. A spatio-kinematic model has been developed for ETHOS 1, indicating that its spectacular polar outflows are kinematically older than the central region of the nebula. This finding is discussed in the context of binary evolution, and it is concluded that the polar outflows in these nebulae are probably formed before their central binaries have entered the common-envelope phase. The central star of ETHOS 1 has yet to be the subject of detailed study, and as such, the orientation of the nebula could not be compared to that of its central binary. A spatio-kinematical analysis of SuWt 2 is presented, proving that the nebular ring is in fact at the waist of a much larger, extended bipolar structure. SuWt 2 is not known to contain a post-main sequence central star, required to eject and ionise the nebular shell, but rather a double A-type binary. The results of the analysis are discussed with relation to possible formation scenarios for SuWt 2. It is concluded that, while neither component of the double A-type binary could be the nebular progenitor, the presence of a third component to the system, which would have been the progenitor, cannot be ruled out. However, as there is no evidence that the central star of SuWt 2 is a binary alone, it is suggested that SuWt 2 should be removed from future lists of planetary nebulae known to host a binary central star. A sample of sixteen central stars of planetary nebulae, displaying morphological traits believed to be typical of central star binarity, were monitored for signs of periodic photometric variability associated with binarity. Six new photometrically variable close-binary stars were discovered, representing a ~15% increase on the previously known figure. The binary detection success rate from this investigation is compared to that of other surveys, and it is concluded that, while the results are promising, a more rigorous test is required to fully assess the extent to which specific morphological traits can be used as indicators of central star binarity.

Subjects/Keywords: 520; Planetary nebulae; Post-common-envelope binary stars

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jones, D. (2011). The influence of central star binarity on the morphologies of planetary nebulae. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-central-star-binarity-on-the-morphologies-of-planetary-nebulae(0d5924db-e0fb-4ebd-bacc-38e8196efb5e).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542694

Chicago Manual of Style (16^th Edition):

Jones, David. “The influence of central star binarity on the morphologies of planetary nebulae.” 2011. Doctoral Dissertation, University of Manchester. Accessed March 07, 2021. https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-central-star-binarity-on-the-morphologies-of-planetary-nebulae(0d5924db-e0fb-4ebd-bacc-38e8196efb5e).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542694.

MLA Handbook (7^th Edition):

Jones, David. “The influence of central star binarity on the morphologies of planetary nebulae.” 2011. Web. 07 Mar 2021.

Vancouver:

Jones D. The influence of central star binarity on the morphologies of planetary nebulae. [Internet] [Doctoral dissertation]. University of Manchester; 2011. [cited 2021 Mar 07]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-central-star-binarity-on-the-morphologies-of-planetary-nebulae(0d5924db-e0fb-4ebd-bacc-38e8196efb5e).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542694.

Council of Science Editors:

Jones D. The influence of central star binarity on the morphologies of planetary nebulae. [Doctoral Dissertation]. University of Manchester; 2011. Available from: https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-central-star-binarity-on-the-morphologies-of-planetary-nebulae(0d5924db-e0fb-4ebd-bacc-38e8196efb5e).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542694

University of Victoria

27. Passy, Jean-Claude. Modeling close stellar interactions using numerical and analytical techniques.

Degree: Dept. of Physics and Astronomy, 2013, University of Victoria

URL: http://hdl.handle.net/1828/4477

► The common envelope (CE) interaction is a still poorly understood, yet critical phase of evolution in binary systems that is responsible for various astrophysical classes… (more)

▼ The common envelope (CE) interaction is a still poorly understood, yet critical phase of evolution in binary systems that is responsible for various astrophysical classes and phenomena. In this thesis, we use various approaches and techniques to investigate different aspects of this interaction, and compare our models to observations. We start with a semi-empirical analysis of post-CE systems to predict the outcome of a CE interaction. Using detailed stellar evolutionary models, we revise the α equation and calculate the ejection efficiency, α, both from observations and simulations consistently. We find a possible anti-correlation between α and the secondary-to- primary mass ratio, suggesting that the response of the donor star might be important for the envelope ejection. Secondly, we present a survey of three-dimensional hydrodynamical simulations of the CE evolution using two different numerical techniques, and find very good agreement overall. However, most of the envelope of the donor is still bound at the end of the simulations and the final orbital separations are larger than the ones of young observed post-CE systems. Despite these two investigations, questions remain about the nature of the extra mechanism required to eject the envelope. In order to study the dynamical response of the donor, we perform one-dimensional stellar evolution simulations of stars evolving with mass loss rates from 0.001 up to a few M⊙/yr. For mass-losing giant stars, the evolution is dynamical and not adiabatic, and we find no significant radius increase in any case. Finally, we investigate whether the substellar companions recently observed in close orbits around evolved stars could have survived the CE interaction, and whether they might have been more massive prior to their engulfment. Using an analytical prescription for the disruption of gravitationally bound objects by ram pressure stripping, we find that the Earth-mass planets around KIC 05807616 could be the remnants of a Jovian-mass planet, and that the other substellar objects are unlikely to have lost significant mass during the CE interaction. Advisors/Committee Members: Herwig, Falk (supervisor), De Marco, Orsola (supervisor).

Subjects/Keywords: Hydrodynamics; Numerics; Binary stars; Stellar evolution; Common Envelope

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Passy, J. (2013). Modeling close stellar interactions using numerical and analytical techniques. (Thesis). University of Victoria. Retrieved from http://hdl.handle.net/1828/4477

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Passy, Jean-Claude. “Modeling close stellar interactions using numerical and analytical techniques.” 2013. Thesis, University of Victoria. Accessed March 07, 2021. http://hdl.handle.net/1828/4477.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Passy, Jean-Claude. “Modeling close stellar interactions using numerical and analytical techniques.” 2013. Web. 07 Mar 2021.

Vancouver:

Passy J. Modeling close stellar interactions using numerical and analytical techniques. [Internet] [Thesis]. University of Victoria; 2013. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1828/4477.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Passy J. Modeling close stellar interactions using numerical and analytical techniques. [Thesis]. University of Victoria; 2013. Available from: http://hdl.handle.net/1828/4477

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Notre Dame

28. Joe Reese Haywood. Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>.

Degree: Physics, 2006, University of Notre Dame

URL: https://curate.nd.edu/show/k0698625s7g

► Developments in numerical relativistic hydrodynamics over the past thirty years, along with the advent of high speed computers, have made problems needing general relativity… (more)

▼ Developments in numerical relativistic hydrodynamics over the past thirty years, along with the advent of high speed computers, have made problems needing general relativity and relativistic hydrodynamics tractable. One such problem is the relativistic evolution of neutron stars, either in a head on collision or in binary orbit. Also of current interest is the detection of gravitational radiation from binary neutron stars, black-hole neutron star binaries, binary black holes, etc. Such systems expected to emit gravitational radiation with amplitude large enough to be detected on Earth by such groups as LIGO and VIRGO. Unfortunately, the expected signal strength is below the current noise level. However, signal processing techniques have been developed which should eventually find a signal, if a good theoretical template can be found. In the cases above it is not possible to obtain an analytic solution to the Einstein equations and a numerical approximation is therefore most necessary. In this thesis the Einstein equations are written using the formalism of Arnowitt, Desser and Misner and a conformally flat metric is assumed. Numerical simulations of colliding neutron stars, having either a realistic or Gamma = 2 polytropic equation of state (EOS), are presented which confirm the rise in central density seen by [51, 89] for the softer EOS. For the binary calculation, the results of Wilson et al. [89] are confirmed, which show that the neutron stars can collapse to black holes before colliding when the EOS is realistic and we also confirm results of Miller [56] and others that there is essentially no compression, the central density does not increase, when the stiffer equation of state is used. Finally, a template for the gravitational radiation emitted from the binary is calculated and we show that the frequency of the emitted gravitational waves changes more slowly for the [89] EOS, which may result in a stronger signal in the 50-100 Hz band of LIGO. Advisors/Committee Members: Grant J. Mathews, Committee Chair.

Subjects/Keywords: binary neutron stars; relativistic hydrodynamics

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APA (6^th Edition):

Haywood, J. R. (2006). Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>. (Thesis). University of Notre Dame. Retrieved from https://curate.nd.edu/show/k0698625s7g

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Haywood, Joe Reese. “Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>.” 2006. Thesis, University of Notre Dame. Accessed March 07, 2021. https://curate.nd.edu/show/k0698625s7g.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Haywood, Joe Reese. “Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>.” 2006. Web. 07 Mar 2021.

Vancouver:

Haywood JR. Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>. [Internet] [Thesis]. University of Notre Dame; 2006. [cited 2021 Mar 07]. Available from: https://curate.nd.edu/show/k0698625s7g.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Haywood JR. Numerical Relativistic Hydrodynamic Simulations of Neutron Stars</h1>. [Thesis]. University of Notre Dame; 2006. Available from: https://curate.nd.edu/show/k0698625s7g

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Canterbury

29. Komonjinda, Siramas. A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph.

Degree: PhD, Astronomy, 2008, University of Canterbury

URL: http://dx.doi.org/10.26021/5921

► Orbits of spectroscopic binary systems have been studied for more than a century. Over three thousand orbits of spectroscopic binary systems have been derived. These… (more)

▼ Orbits of spectroscopic binary systems have been studied for more than a century. Over three thousand orbits of spectroscopic binary systems have been derived. These orbits are based on the radial velocities measured from the spectra recorded by a photographic plate to a high precision spectrum observed from a modern spectrograph. In many cases, the shape of the orbit was assumed to be circular, of hence the eccentricity is zero. This assumption is based on the fact that a small eccentricity (e < 0.1) measured from the observed data might be a result from the error of observations or from the intrinsic variation of a spectroscopic binary system. Sixteen southern spectroscopic binary systems, including twelve single-lined binaries and four double-lined binaries, were selected to study in this research program. These systems were assumed to have circular orbits or have very nearly circular orbits (e < 0.1) from their previous published solutions. The HERCULES spectrograph was used in conjunction with the 1-m McLellan telescope at Mt John University Observatory to collect the spectra of these systems. The observations, taken from October 2004 to August 2007, comprised about 2000 high-resolution spectra of spectroscopic binary systems and standard radial-velocity stars. Radial velocities of spectroscopic binary systems were measured from these spectra and orbital solutions of the systems were derived from these radial velocities. It was found that from HERCULES data, we are able to achieve high-precision orbital solutions of all the systems studied. The best-fit solutions can be improved as much as 70 times from the literature’s orbital solutions. It has been found that the precision of a system depends on the rotational velocities of the components as well as the level of their chromospheric activity. We are able to confirm the eccentricity in the orbit of only one of the selected spectroscopic binary systems, HD194215. Its eccentricity is 0.123 29 ± 0.000 78. The small eccentricities of other systems are not confirmed. There are four systems; HD22905, HD38099, HD85622 and HD197649, that have circular orbital solutions from the large errors in their measured eccentricities. Two systems, HD77258 and HD124425, have too small eccentricities, e = 0.000 85±0.000 19 and 0.002 60 ± 0.000 99 to be acceptable. An intrinsic variation is a presumed cause of the spurious eccentricities derived from the data of the other eight systems. Photometric data from Mt John University Observatory service photometry program, as well as the photometric data from the Hipparcos satellite and information of these systems from the literature, using various methods and instruments, give a wider view on the systems’ behaviour. It is possible that the spurious eccentricities derived for these systems result from the eclipsing behaviour of a system (HD50337), or from the nature of the components, such as, the distortion of their shape (HD352 and HD136905), their chromospheric activity (HD9053, HD3405, HD77137,…

Subjects/Keywords: Binary stars; Spectroscopic analysis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Komonjinda, S. (2008). A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph. (Doctoral Dissertation). University of Canterbury. Retrieved from http://dx.doi.org/10.26021/5921

Chicago Manual of Style (16^th Edition):

Komonjinda, Siramas. “A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph.” 2008. Doctoral Dissertation, University of Canterbury. Accessed March 07, 2021. http://dx.doi.org/10.26021/5921.

MLA Handbook (7^th Edition):

Komonjinda, Siramas. “A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph.” 2008. Web. 07 Mar 2021.

Vancouver:

Komonjinda S. A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph. [Internet] [Doctoral dissertation]. University of Canterbury; 2008. [cited 2021 Mar 07]. Available from: http://dx.doi.org/10.26021/5921.

Council of Science Editors:

Komonjinda S. A study of binary star orbits using precise radial velocity measurements with the HERCULES spectrograph. [Doctoral Dissertation]. University of Canterbury; 2008. Available from: http://dx.doi.org/10.26021/5921

University of Sydney

30. Kok, Yitping. Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI .

Degree: 2013, University of Sydney

URL: http://hdl.handle.net/2123/10028

► This thesis describes the development of an astrometric facility at the Sydney University Stellar Interferometer (SUSI) with an aim to measure at high precision the… (more)

▼ This thesis describes the development of an astrometric facility at the Sydney University Stellar Interferometer (SUSI) with an aim to measure at high precision the relative astrometry of bright close binary stars and ultimately to detect the presence of exoplanets within those binary star systems through observations of the systems’ perturbed motion. At the core of the facility is a new beam combiner that is phase-referenced to an existing primary beam combiner in the visible wave- length regime. The latter provides post-processed fringe-tracking information to the former for fringe stabilization and coherent integration of pre-recorded stellar fringes using newly developed data reduction software. Interference fringe packets of a binary star are recorded alternately; first the fringe packet of the primary, then the secondary, finally back to the primary again. The measurement of the fringe packet separation is facilitated by an air-filled differential delay line and a network of interferometer-based metrology systems. Characterizations and initial astronomical observations carried out with the dual beam combiner setup demonstrated for the first time the success of the dual-star phase-referencing technique in visible (~1μm) wavelengths. The current astrometric precision is larger than 100μas while the long term astrometric accuracy is yet to be characterized. In a parallel development, a complementary observing method using only the primary beam combiner is also demonstrated in this thesis. Relative astrometry of binary stars up to ~0.8” separation with this technique has been demonstrated to have precision of better than 100μas. A simple detection limit analysis based on a list of target binary stars estimates up to two exoplanet detections can be achieved with SUSI if the new astrometric facility attains precision of 10μas while the primary beam combiner operates at its designed peak performance. Finally, one new stellar companion was resolved and a preliminary astrometry for another suspected companion was estimated from the astronomical observation data collected throughout the course of this thesis.

Subjects/Keywords: optical long baseline interferometry; visible wavelengths; metrology; binary stars

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kok, Y. (2013). Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI . (Thesis). University of Sydney. Retrieved from http://hdl.handle.net/2123/10028

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kok, Yitping. “Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI .” 2013. Thesis, University of Sydney. Accessed March 07, 2021. http://hdl.handle.net/2123/10028.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kok, Yitping. “Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI .” 2013. Web. 07 Mar 2021.

Vancouver:

Kok Y. Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI . [Internet] [Thesis]. University of Sydney; 2013. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2123/10028.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kok Y. Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI . [Thesis]. University of Sydney; 2013. Available from: http://hdl.handle.net/2123/10028

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations