Download or read book Modeling the Stellar Environment written by P. DELACHE (Ed) and published by Atlantica Séguier Frontières. This book was released on 1989 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Stellar Environment written by Institut d'astrophysique (Paris, France) and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Download or read book Stellar Astrophysics written by Roger John Tayler and published by Taylor & Francis Group. This book was released on 1992 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stellar Astrophysics contains a selection of high-quality papers that illustrate the progress made in research into the structure and evolution of stars. Senior undergraduates, graduates, and researchers can now be brought thoroughly up to date in this exciting and ever-developing branch of astronomy.
Download or read book Characterizing Stellar and Exoplanetary Environments written by Helmut Lammer and published by Springer. This book was released on 2014-11-03 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book an international group of specialists discusses studies of exoplanets subjected to extreme stellar radiation and plasma conditions. It is shown that such studies will help us to understand how terrestrial planets and their atmospheres, including the early Venus, Earth and Mars, evolved during the host star’s active early phase. The book presents an analysis of findings from Hubble Space Telescope observations of transiting exoplanets, as well as applications of advanced numerical models for characterizing the upper atmosphere structure and stellar environments of exoplanets. The authors also address detections of atoms and molecules in the atmosphere of “hot Jupiters” by NASA’s Spitzer telescope. The observational and theoretical investigations and discoveries presented are both timely and important in the context of the next generation of space telescopes. The book is divided into four main parts, grouping chapters on exoplanet host star radiation and plasma environments, exoplanet upper atmosphere and environment observations, exoplanet and stellar magnetospheres, and exoplanet observation and characterization. The book closes with an outlook on the future of this research field.
Download or read book The Art of Modeling Stars in the 21st Century IAU S252 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2008-12-18 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stellar models are the very basic building blocks with which we build up our knowledge of the Universe. New numerical experiments are heralding a new level of sophistication in our ability to model, and understand, how stars work. This volume provides an overview and the most recent advances in modeling of stellar structure and evolution. Modeling of stars relies on our understanding of the detailed physical processes happening in stars, and the most recent observations of stars made by modern large telescopes and current high technologies. IAU Symposium 252 presents the most recent developments in five key areas, including: improvements of the physical ingredients of stellar models; the evolution of low and intermediate mass stars; the evolution of massive stars; close binary evolution; and stellar physics in the era of very large telescopes. This overview of stellar research is at a level suitable for research astronomers and graduate students.
Download or read book Stellar Modeling with Low temperature On the fly Opacity written by Lynn Buchele and published by . This book was released on 2021 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate stellar modeling requires using our understanding of phenomena far smaller than humans can observe to study some of the largest objects in the universe. One quantity that bridges this gap is the mean opacity, which uses knowledge about atomic and molecular interactions with light to inform how photons carry energy through a star. As the mean opacity depends on both the quantum mechanics of atoms and molecules and the macroscopic properties of the star (temperature, density, composition) it can be tricky to calculate. Traditionally, stellar modeling programs avoid the time-consuming computation of opacity by interpolating off of pre-made opacity tables. However, this interpolation introduces the possibility of error. In low-temperature areas of a star (less than 10,000K), this error is likely to be largest when the composition of the star differs from the composition used to create the tables. One way to examine this error is to model stars using low-temperature opacity values calculated on-the-fly. In this case, on-the-fly means using opacity calculated as the star is being modeled by a low-temperature opacity code using the exact temperature, density, and composition of each region within the star. This work describes the process of adapting the Atlas Opacity Program (ATOP) for use as an on-the-fly opacity code and discusses the results of using on-the-fly opacity values for several stellar evolution models created with the Modules for Experiments in Stellar Astrophysics (MESA) code. These models show that the effect of using on-the-fly opacity is more pronounced in models where the relative abundance of carbon to oxygen in the outer layers of the star changes significantly over the course of the star’s evolution.
Download or read book Ecology of Blue Straggler Stars written by Henri M. J. Boffin and published by Springer. This book was released on 2014-12-03 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book.
Download or read book Stars and Stellar Processes written by Mike Guidry and published by Cambridge University Press. This book was released on 2019-02-07 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the physics of stars in relation to modern topics such as neutrino oscillations, supernovae, black holes, and gravitational waves.
Download or read book Semi analytic Modeling of Stellar Populations in Astrophysical Simulations written by Brian David Crosby and published by . This book was released on 2016 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stellar Structure and Evolution written by Rudolf Kippenhahn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The text presents an overview of the models developed to explain the stability, dynamics and evolution of the stars, and great care is taken to detail the various stages in a star's life. The authors have succeeded in producing a unique text based on their own pioneering work in stellar modeling. Since its publication, this textbook has come to be considered a classic by both readers and teachers in astrophysics. This study edition is intended for students in astronomy and physics alike.
Download or read book Dynamical Evolution of Star Clusters Confrontation of Theory and Observations written by Piet Hut and published by Springer. This book was released on 1996-06-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews recent progress in the study of dynamics of star clusters. The meeting focused on the enormous progress of both the observation and the theoretical modeling of star clusters. New results from the refurbished Hubble Space Telescope (HST) include the mass function down to the hydrogen burning limits, white dwarf sequence, and central density profiles of `post-collapse' clusters by star counts. On the theoretical side, this symposium saw the first direct evidence of gravothermal oscillation through N-body simulation, which was made possible by GRAPE-4, the dedicated special-purpose computer for N-body simulation. Numerical techniques to combine stellar evolution and dynamical evolution of the cluster were presented. The book will be of primary interest to astrophysicists.
Download or read book The Formation of Stars written by Steven W. Stahler and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text for physics and astronomy graduate students, and as a reference for professional scientists.
Download or read book Molecules in the Stellar Environment written by Uffe G. Jorgensen and published by Springer. This book was released on 1994-04-05 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gives and excellent survey of our present knowledge of molecularprocesses in stellar and proto-stellar objects. It reviews molecular physicsin stellar environments and is intended to bridge the gap between astrophysicists and chemists. The topics range from the theoretical to the computational and include observational data. Among the topics treated are questions of stellar evolution, the determination of physical propertiesand structures , and the chemical composition of stellar protospheres. Opacity is studied in the context of various types of stellar and proto-stellar objects.
Download or read book The Circumstellar Environment of Evolved Stars as Revealed by Studies of Circumstellar Water Masers written by Kevin Marvel and published by Universal-Publishers. This book was released on 1996-12 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dissertation presents the results of a multi-epoch very long baseline interferometric study of water masers located in the extended atmospheres of evolved stars. The research was performed using the Very Long Baseline Array and Very Large Array of the National Radio Astronomy Observatory. Optical monitoring of the stars was provided by the American Association of Variable Star Observers, the Variable Star Network and Dr. Bill Neely of the NF/Observatory. Water masers of found to exist in a region where a population inversion of the rotation transition of 22 GHz can be maintained by collisional pumping. The masers are identified as individual pockets of gas, which have the good velocity coherence and may be imaged using radio interferometry. Stellar winds are initiated in these sources by dust formation and acceleration of the gas through momentum coupling. The typical wind speeds in the region of the water masers are 10 to 20 km/s The water masers are followed through several epochs of observation and exhibit proper motions consistent with the assumed source distance and the measured outflow of velocity in the water maser region. Estimates of the distance to the sources using statistical approximation are in agreement with the currently accepted distances to the stars. A detailed kinematic model is used to describe the flow motions of the gas in the maser region. The regions are found to be complex and not well modeled by uniform radial outflow, radial outflow with rotation, or radial with acceleration. The reasons for this are explored and include anisotropic velocity fields induced through non-uniform dust formations near the star and incomplete sampling of the outflow due to a lack of detected masers. Possibilities for future work in the subject are described and include more sophisticated modeling, more sensitive observations, and analysis of other maser species.
Download or read book Modeling the Light from Variable Stellar Systems with Graphics Processing Units written by and published by . This book was released on 2015 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout stellar astronomy, there exist many classes of stars which exhibit various surface inhomogeneities, velocity perturbations, and/or non-spherical geometries, often varying in time. To model spectra for any of these stars requires projecting a model of that star in the sky and deriving a unique specific intensity for each of the various surface features and then summing the resulting contributions to the flux. While this task is relatively straightforward, it is difficult to generalize for all the classes of stars befitting such spectral modeling, and more importantly, it is a computationally expensive task. As such, many different spectral modeling tools have been developed over the years for dealing with any one of a given class of these stars. In this thesis, I present a generalized approach to this task, the GLASS method. Relying on computer graphics techniques and technology, the GLaDoS code is introduced as an implementation of the GLASS method. With its introduction, I show that GLaDoS is capable of generally treating the problem of computing spectra for an array of variable stellar systems, particularly W UMa contact binaries, spotted stars, and non-radially pulsating stars. As further evidence of its robustness in handling time-varying systems, focus is paid to extensively modeling additional systems. In particular, I construct a binary model focusing on the effect radiation from the companion can have on each star, and pulsation modes are identified for gamma Doradus pulsator HD 135825. The binary model requires adequate handling of variable surface inhomogeneities and non-spherical geometries. Mode identification additionally requires treating inhomogeneities, but it additionally necessitates management of the computationally expensive derivation of thousands to millions of unique spectra that can be fit against observed time-series spectra. Together, these modeling efforts present a thorough trial for the GLASS method and GLaDoS code and show them capable of generally handling spectral modeling in a computationally efficient manner.
Download or read book Late Stages of Stellar Evolution Computational Methods in Astrophysical Hydrodynamics written by C.B. de Loore and published by Springer. This book was released on 2014-03-12 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of 7 lectures is intended to be a textbook for graduate students who want to learn about modern developments in astronomy and astrophysics. The first part surveys various aspects of the late stages of stellar evolution, including observation and theory. B.C. de Loore's long article on stellar structure is followed by reviews on supernovae, on circumstellar envelopes, and on the evolution of binaries. The second part deals with the important problem of modeling stellar evolution based on the computational hydrodynamics.
