Download or read book Towards Spectroscopic Detection of Low Mass Ratio Stellar Binary Systems written by Kevin Carl Gullikson and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detection of the emission from the secondary component in a binary system can be extremely challenging, but equally rewarding. In the case of intermediate to high-mass binaries, detection of close companions can inform formation theories. In the extreme low mass-ratio case, where the secondary component is in fact a planet, detection of the emission in high resolution spectroscopy can be used to determine the true planet mass. In this thesis, we describe a technique to detect the thermal emission from the secondary component of a low mass-ratio binary system. We apply this technique to archived observations of early B-type stars using VLT/CRIRES, and simulate future observations of planetary systems with IGRINS, a near-infrared spectrograph being built now.
Download or read book Spectroscopic Detection and Characterization of Extreme Flux ratio Binary Systems written by Kevin Carl Gullikson and published by . This book was released on 2016 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 unique probe into the conditions of the collapsing cloud core and circumstellar disk(s) of the binary fragments. Inside a ~1000 AU the disks from the two forming stars can interact, and additionally companions can form directly through disk fragmentation. We might therefore expect the mass-ratio distribution of close companions to differ from that of wide companions. This prediction is difficult to test with intermediate-mass primary stars using traditional methods because the contrast ratios that would be required to detect low-mass companions at narrow working angles are not yet achievable. In this thesis, we present a spectroscopic method to detect and characterize close companions to a variety of stars. We demonstrate applications of the method to detection of stars and even planets around sun-like stars, and present the results of a survey searching for companions to A- and B-type stars. As part of the survey, we estimate the temperatures and surface gravity of most of the 341 sample stars, and derive their masses and ages. We additionally estimate the temperatures and masses of the 64 companions we find, 23 of which are new detections. We find that the mass-ratio distribution for our sample has a turnover near q ~0.3, in contrast to the scale-free power law that describes the widely separated binary systems. We take this characteristic scale as evidence that companions are accreting a significant of material through disk interactions as they form, and that the scale is largely set by the disk lifetime and the time at which the fragments form.
Download or read book A Guide to Close Binary Systems written by Edwin Budding and published by CRC Press. This book was released on 2022-05-12 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Close Binary Systems provides a comprehensive survey and guide to the fast-moving field of multiple, specifically binary, stars, with an up to date account of research around 'close', i.e. interacting pairs. Such interactions allow direct quantification of stellar properties, opening up factual insights into basic building blocks of the Universe. The book provides a much needed update for the seminal Close Binary Systems of Zdenĕk Kopal. Following a comparable plan, it presents relevant subject matter with an emphasis on building a framework of understanding to serve as a supporting resource for students and researchers. The text starts from a general historical background and progresses into the main theoretical ideas supporting our prima facie interpretation of observations. The central chapters explore further into these observational methods, arranged according to the classic subdivisions of astrometry, spectroscopy and photometry. Optimal inversion of observational data into model parametrization is a theme through these chapters. Significant here is the problem of how non-uniqueness in modelling affects interpretation. The underlying issues of stellar evolution bearing on observational evidence become paramount in the last four chapters. The book proceeds step-by-step from directly understandable examples of unevolved pairs to the challenging cases where stars are found in more and more extreme conditions, leading up to the mergers of massive black hole pairs seen in the new field of gravitational wave astronomy. This is a valuable reference for postgraduate and advanced undergraduate students working in mainstream areas of stellar astrophysics, with applications also to exoplanet research which shares some methodological features. Course designers for stellar astrophysics will find a useful selection of topics within this book. Key features: • Provides a well-explained and backgrounded, up-to-date account of close binary systems, in a fast-moving field of research that is growing in scientific importance • Surveys a wide range of case-studies within the context of binary and multiple star systems • Fills an acknowledged gap in current literature Cover Image: A public memorial to Zdenek Kopal in his home town (birthplace) of Litomysl in Czechia.
Download or read book Parameter determination of a binary star system written by Fabian Prilasnig and published by GRIN Verlag. This book was released on 2008-03-13 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diploma Thesis from the year 2001 in the subject Astronomy, grade: 1,0, Technical University of Graz, language: English, abstract: The focus of this work about binary star systems is on model applications ans selections of an algorithm to determine the parameters of individual binaries. It consists of four major parts: a general introduction to the theory of binary stars; introductory material about spectroscopy and photometry; a description of IRAF (Imaging Reduction and Analysis Facility) - this is a software program which allows the reduction and the analysis of gathered data of astronomical objects - and its application on parameter determination of the binary system UV Leonis. Last but not least follows the presentation of the spectroscopical and photometrical results of this binary star system. The spectroscopical and photometrical results confirm that the components of the binary star system UV Leonis are main-sequence stars having the same spectral type as the Sun. From the radial velocity curves we can conclude that both components must be nearly spherical due to the sinusoidal shape of their radial velocity curves. The characteristics of their B and V light curves tell us that the orbital inclination is a little bit smaller than 90° because of the V-shaped eclipses. Our results agree with the results from the literature, while masses were spectroscopically determined here for the first time. Our value of the distance to UV Leo is consistent with trigonometric parallax from the Hipparcos mission but our error bar is smaller.
Download or read book Binary Stars as Critical Tools and Tests in Contemporary Astrophysics IAU S240 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2007-08-27 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU S240 focuses on recent advances across the broad field of binary star research.
Download or read book Planets in Binary Star Systems written by Nader Haghighipour and published by Springer Science & Business Media. This book was released on 2010-06-03 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1988, in an article on the analysis of the measurements of the variations in the radial velocities of a number of stars, Campbell, Walker, and Yang reported an - teresting phenomenon;the radial velocity variations of Cephei seemed to suggest the existence of a Jupiter-like planet around this star. This was a very exciting and, at the same time, very surprising discovery. It was exciting because if true, it would have marked the detection of the ?rst planet outside of our solar system. It was surprising because the planet-hosting star is the primary of a binary system with a separation less than 19 AU, a distance comparable to the planetary distances in our solar system. The moderatelyclose orbit of the stellar companionof Cephei raised questions about the reality of its planet. The skepticism over the interpretation of the results (which was primarily based on the idea that binary star systems with small sepa- tions would not be favorable places for planet formation) became so strong that in a subsequent paper in 1992, Walker and his colleagues suggested that the planet in the Cephei binary might not be real, and the variations in the radial velocity of this star might have been due to its chromospheric activities.
Download or read book Photometric and Spectroscopic Binary Systems written by E.B. Carling and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 571 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our conference - opening today - has two aims in view: first, to commemorate some milestones in the development of the studies of close binary systems whose anniversaries fall in these years, as well as to take stock of our present knowledge accumulated through out preceding decades, in order to consider where do we go from here. This summer, 310 years will have elapsed since the first ec lipsing binary - Algol - was discovered in Bologna by Geminiano Montanari (1633-1687) to be a variable star; and 198 years have gone by since John Goodricke of York (1764-1786) established the fact that Algol's light changes were periodic. Moreover, it is al most exactly (to a month) now 100 years since Edward Charles Pickering (1846-1919) of Harvard Observatory in the United States took the first steps towards the development of systematic methods of analysis of the light changes of Algol and related systems - a topic which will constitute the major part of the programme of our present conference. The three dates recalled above illustrate that the discoverers of such celestial objects and observers of their light changes have been systematically ahead of the theoreticians endea vouring to understand the significance of the observed data by de cades and centuries in the past - a fact which, incidentally, con tinues to hold good (albeit with a diminishing lead-time) up to the present.
Download or read book The Influence of Binaries on Stellar Population Studies written by D. Vanbeveren and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews recent observations of non-evolved and evolved binary populations in clusters and the field with special emphasis on statistical biases, incompleteness, and distribution functions. It considers different binary types and presents and discusses recent results in the field.
Download or read book Close Binaries in the 21st Century New Opportunities and Challenges written by Alvaro Gimenez and published by Springer Science & Business Media. This book was released on 2007-04-05 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the proceedings of an international conference entitled "Close Binaries in the 21st Century: New Opportunities and Challenges", held in Syros island, Greece, June 27-30, 2005. The papers collected in this volume detail the latest achievements in the field and reflect the state of the art of the dynamically evolving area of binary star research.
Download or read book The Impact of Binary Stars on Stellar Evolution written by Giacomo Beccari and published by Cambridge University Press. This book was released on 2019-04-18 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stars are mostly found in binary and multiple systems, with at least 50% of all solar-like stars having companions; this fraction approaches 100% for the most massive stars. A large proportion of these systems interact and alter the structure and evolution of their components, leading to exotic objects such as Algol variables, blue stragglers and other chemically peculiar stars, but also to phenomena such as non-spherical planetary nebulae, supernovae and gamma-ray bursts. While it is understood that binaries play a critical role in the Initial Mass Function, the interactions among binary systems significantly affect the dynamical evolution of stellar clusters and galaxies. This interdisciplinary volume presents results from state-of-the-art models and observations aimed at studying the impact of binaries on stellar evolution in resolved and unresolved populations. Serving as a bridge between observational and theoretical astronomy, it is a comprehensive review for researchers and advanced students of astrophysics.
Download or read book An Introduction to Close Binary Stars written by R. W. Hilditch and published by Cambridge University Press. This book was released on 2001-03-12 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary systems of stars are as common as single stars. They are of fundamental importance because they allow stellar masses, radii and luminosities to be measured directly, and explain a host of diverse and energetic phenomena including X-ray binaries, cataclysmic variables, novae, symbiotic stars, and some types of supernovae. This 2001 book was the first to provide a pedagogical and comprehensive introduction to binary stars. It combines theory and observations at all wavelengths to develop a unified understanding of binaries of all categories. It comprehensively reviews methods for calculating orbits, the Roche model, ideas about mass exchange and loss, methods for analysing light curves, the masses and dimensions of different binary systems, and imaging the surfaces of stars and accretion structures. This book provides a thorough introduction to the subject for advanced undergraduate and graduate students. Researchers will also find this to be an authoritative reference.
Download or read book The Realm of Interacting Binary Stars written by J. Sahade and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: More than two centuries have elapsed since the story of the interacting binary stars began with the rediscovery of the variability of Algol by John Goodricke and the interpretation he proposed for explaining the regular periodic brightness variations which he found. Over this long span of time our knowledge about these systems has been growing, and we have now reached a fairly good understanding of the structure and behavior of this interesting group of objects. This book contains a timely summary of our present knowledge of interacting binary stars. The chapters have been written by distinguished scientists who have done relevant research in the field of interacting binary stars.
Download or read book Binaries as Tracers of Stellar Formation written by Antoine Duquennoy and published by Cambridge University Press. This book was released on 1992-11-26 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: More than two-thirds of stars belong to multiple stellar systems. Binary stars are considered now as one of the best constraints on stellar formation models. Not only do binaries keep memory of their birth conditions but their orbit will also be subjected to changes by tidal effects, wind accretion and encounters in clusters. Certainly the correlation between orbital eccentricity and period is a clue to our understanding of double star history. These proceedings aim to disentangle evidence of stellar formation from later physical evolution. Each article in this 1992 volume is a paper that was read at a meeting organized to honour Dr Roger Griffin of the University of Cambridge for his pioneer work in galactic astronomy, dynamics of clusters and study on binary stars due to his cross-correlation technique to determine stellar radial velocities.
Download or read book Binary and Multiple Systems of Stars written by Alan H. Batten and published by Elsevier. This book was released on 2013-10-22 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary and Multiple Systems of Stars focuses on spectroscopic observational results and interpretations of binaries, and a few of multiple systems. Organized into 10 chapters, this book begins with the basic concepts and terminologies used in the study of binary and multiple systems of stars. Then, the incidence of both star systems is described. Subsequent chapters explore the properties of individual binaries, as well as the evolution and origin of such star system. This book will be a valuable reference material for astronomers, scientists in related fields, as well as graduate students.
Download or read book Stellar Binaries at the Galactic Center written by Devin Satoru Chu and published by . This book was released on 2020 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis performs unprecedented investigations for spectroscopic binaries at the Galactic center and utilizes the development and extended observing baseline of integral field spectroscopy behind adaptive optics. The second chapter of this thesis describes the first direct search for binarity of its kind for the star S0-2, the most well-studied star of the S-star cluster. Almost two decades of spectroscopic with adaptive optics has led to the capability to look for a binary signal in S0-2's spectroscopic data. We introduce a methodology for investigating periodicity and placing limits on binary parameters with radial velocity data. We do not detect any signs of binarity for S0-2 and place limits on a hypothetical companion mass for S0-2 to be 1.6 solar masses, which is below current detection limits. We also investigate and find that a feasible spectroscopic binary system would not bias the detection of relativistic redshift, a post-Newtonian spectroscopic measurement. The third chapter of this thesis explains the improvements in spectral analysis that lead to greater sensitivity to spectroscopic binary systems. We use a new method for measuring radial velocity measurements of stars at the Galactic center. This new method utilizes spectral fitting software and a new infrared spectral grid that finally covers effective temperatures of 30,000 K, putting the young, massive S-stars at the Galactic center within reach. We improve the precision of our radial velocities by a factor of 1.7. We also test our methodology on radial velocity standard stars and find that the new method eliminates the slight bias of our previous method. These characteristics of this method make us more sensitive to detecting the radial velocity variations of spectroscopic binary stars. The fourth chapter presents a systematic search for spectroscopic binaries at the Galactic Center. With over two decades of integral field spectroscopy data, advanced tools for fitting mid-infrared stellar spectra, and 1000 radial velocity data points, we conduct a spectroscopic binary search of 29 stars at the Galactic center. After subtracting a star's motion around the supermassive black hole, we search for a periodic signal using a Lomb-Scargle analysis and fitting the residual radial velocity curve to a binary system radial velocity curve. We find no significant periodic detections in our sample, suggesting there are no binaries among the S-stars. We also place limits on the hypothetical companion masses of these S-stars. We also place a limit on the intrinsic binary fraction of these stars at 42%, which disagrees with the binary fraction for massive field stars. These results favor S-star formation mechanisms that result in a low binary fraction. The final chapter presents new integral field spectroscopic observations of stars in the nuclear star cluster. We present data taken over 6 years and add the spectral types of 169 stars: 47 of which are Wolf-Rayet and O/B stars, and the remaining 122 are K and M giants. This addition to the rich Galactic center integral field spectroscopy data set provides opportunities to further study stellar demographics and dynamics of the nuclear star cluster.
Download or read book Spectral Atlas for Amateur Astronomers written by Richard Walker and published by Cambridge University Press. This book was released on 2017-07-20 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: A full colour reference featuring detailed commented spectral profiles of more than one hundred astronomical objects.
Download or read book Active Close Binaries written by Cafer Ibanogammalu and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the 1970s symposia or colloquia devoted to recent research on close binaries have been held around the world almost annually. At meetings of the General Assembly of the International Astronomical Union this topic has also been discussed in detail at presentations in various commission meetings and also as invited talks by leading astronomers in the field. In recent years, fundamental changes have taken place in the study of close binaries due to the improvements in observational techniques, extension of observations from X-ray to radio regions of the electromagnetic spectrum, and advances in theoretical studies. For more than a decade, a group of astronomers at Ege University Observatory has been concentrating on active close binaries with particular emphasis on the behaviour of the light curves of chromospherically active systems. Thus, we decided to organize an international meeting in Western Anatolia, where this part of Turkey had been the cradle for great developments in science during antiquity. KUljadasi, located only minutes away from Ephesus, one of the seven wonders of the world, was selected to be the meeting site. Close binary systems constitute a very rich source of information about the physical properties of the component stars. Some systems are eclipsing variables, where periodic recurrences of eclipses are observed as comparatively brief decreases in the total brightness of the binary system. Precise methods of photometric observations make it possible to obtain the light variations of these systems because of eclipses and other phenomena.
