Download or read book The Structure and Evolution of Planetary Nebulae with Very Hot Nuclei written by Nicholas Andrew Walton and published by . This book was released on 1987 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hot Planetary Nebulae Nuclei and Related Objects written by Letizia Stanghellini and published by . This book was released on 1995 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hottest central stars found in planetary nebulae excite the O VI atomic transition in their atmospheres. Presumably the central stars of all planetary nebulae become O VI stars during some phase of their evolution. Observational studies show that all post-asymptotic giant branch (P-AGB) stars (excluding white dwarfs) that undergo nonradial pulsations are O VI stars. A full understanding of O VI stars is therefore crucial before we can develop a complete picture of P-AGB evolution. In this thesis we study O VI central stars of planetary nebulae, with particular attention to obtaining their evolutionary paths, masses and an understanding of the physical processes of the associated nebulae. Our approach is to use analyses of nebular and stellar spectral features as diagnostics of the physical conditions that prevail in and around these objects. We obtain stellar magnitudes, Zanstra temperatures, extinction constants, abundances, and other diagnostics. By placing the central stars on the HR diagram, we estimate their masses and evolutionary timescales. Correlations between spectral characteristics and observable stellar properties suggest that narrow-line and broad-line O VI central stars belong to different mass-groups. We also calculate the nebular electron densities and distances for a larger sample of planetary nebulae and demonstrate the existence of correlations between the different density diagnostics, in substantial agreement with leading hydrodynamical models. We perform theoretical studies of instability against nonradial oscillations of hydrogen-depleted P-AGB stars and white dwarfs. Our tests of instability, which are non-adiabatic and are based on stellar surface models combined with evolutionary models, are in agreement with nonradial oscillations found from photometric measurements in O VI central stars and other hydrogen-depleted evolved stars.
Download or read book Hot Planetary Nebulae Nuclei written by Letizia Stanghellini and published by . This book was released on 1995* with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics and Dynamics of Planetary Nebulae written by Grigor A. Gurzadyan and published by Springer Science & Business Media. This book was released on 2013-04-09 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planetary nebulae are the classic subject of astrophysics. The physical pro cesses occurring in this highly ionized gaseous medium, the formation of emis sion lines in clearly specified conditions, the continuous emission extending from the far ultraviolet up to infrared and radio frequencies, the generation of exotic forms of radiation predicted by atomic physics, along with methods for deciphering the observed spectra and detecting physical and kinematic parameters of the radiating medium, etc. - all these problems form the solid foundations of the physical theory of gaseous nebulae. They are an essential part of the arsenal of powerful tools and concepts without which one cannot imagine understanding and interpreting the enormous diversity of processes taking place in the Universe - in gaseous envelopes surrounding the stars of various classes, from cool dwarfs and flare stars up to hot supergiants, as well as in stellar chromospheres and coronae, in atmospheres of unstable and anomalous stars, in circumstellar clouds and gaseous shells born in nova and supernova explosions, in diffuse nebulae and the interstellar medium, in interacting binary systems, in galaxies with emission lines, in quasars, etc. The last thirty years have seen a turning-point in our knowledge concern ing the very nature of planetary nebulae (PNs). The radio emission of PNs was discovered after it was predicted theoretically. On the other hand, the powerful infrared emission discovered both in the continuum and in emission lines was never expected.
Download or read book Planetary Nebulae written by G.A. Gurzadyan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: The publication in English of this monograph seems to me to indicate the ever increasing interest of astrophysicists in the physical and dynamical problems of planetary nebulae-one of the most interesting and fruitful branches of theoretical astrophysics. Their interest in part arises from the fact that the methods of identify ing the physical processes occurring in planetary nebulae, as well as the many theo retical results, are now acquiring a degree of uni versality as their sphere of application increases. Finally, the special cosmic significance of planetary nebulae is becoming apparent. The English edition of Planetary Nebulae differs considerably from the Russian version published in 1962, primarily because of the new results included in it, but also because of numerous editorial revisions. The problems of magnetic fields and hydrodynamics in planetary nebulae are beginning to occupy an important place in the study of the dynamics of these objects. Recent studies by D. H. Menzel confirm the idea advanced in the present mono graph as to the existence of magnetic fields in planetary nebulae. New light is being cast on the dynamics of planetary nebulae by the hydrodynamic investigations of F. D. Kahn, W. G. Mathews and others. Unfortunately I was not able to include these and other interesting results in the present edition.
Download or read book The Temperatures of the Nuclei of Planetary Nebulae written by Richard Hugh Stoy and published by . This book was released on 1933 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Planetary Nebulae written by Jason J. Nishiyama and published by Morgan & Claypool Publishers. This book was released on 2018-05-25 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we will look at what planetary nebulae are, where they come from and where they go. We will discuss what mechanisms cause these beautiful markers of stellar demise as well as what causes them to form their variety of shapes. How we measure various aspects of planetary nebulae such as what they are made of will also be explored. Though we will give some aspects of planetary nebulae mathematical treatment, the main points should be accessible to people with only a limited background in mathematics. A short glossary of some of the more arcane astronomical terms is at the end of the book to help in understanding. Included at the end of each chapter is an extensive bibliography to the peer reviewed research on these objects and I would encourage the reader interested in an even deeper understanding to read these articles.
Download or read book The Origin and Evolution of Planetary Nebulae written by Sun Kwok and published by Cambridge University Press. This book was released on 2000-05-25 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative volume provides a comprehensive review of the origin and evolution of planetary nebulae. It covers all the stages of their evolution, carefully synthesizes observations from across the spectrum, and clearly explains all the key physical processes at work. Particular emphasis is placed on observations from space, using the Hubble Space Telescope, the Infrared Space Observatory, and the ROSAT satellite. This book presents a thoroughly modern understanding of planetary nebulae, integrating developments in stellar physics with the dynamics of nebular evolution. It also describes exciting possibilities such as the use of planetary nebulae in determining the cosmic distance scale, the distribution of dark matter and the chemical evolution of galaxies. This book provides graduate students with an accessible introduction to planetary nebulae, and researchers with an authoritative reference. It can also be used as an advanced text on the physics of the interstellar medium.
Download or read book Planetary Nebulae written by Harm J. Habing and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planetary nebulae present a fascinating range of shapes and morphologies. They are ideal laboratories for the study of different astrophysical processes: atomic physics, radiative transfer, stellar winds, shocks, wind-wind interaction, and the interaction between stellar winds and the interstellar medium. In addition, planetary nebulae provide information about the late stages of stellar evolution. In the last five years studies of planetary nebulae have progressed very rapidly and new phenomena and insights have been gained. This is partly due to new observations (e.g. from the Hubble Space Telescope, the ISO satellite and new infrared and millimeter spectrographs) and partly to the advancement of hydrodynamic simulations of the structures of planetary nebulae (PN). Many of these new results were reported at IAU Symposium 180 in Groningen, the Netherlands, on August 26 to 30, 1996. This symposium was dedicated to one of the pioneers of PN research: Stuart Pottasch. These proceedings contain chapters on: Introduction to PN with the basic parameters Distances of PN The central stars of PN The envelopes of PN The evolution from AGB to PN The evolution from PN to white dwarfs PN in the galactic context PN in extragalactic systems The future of PN research . The book contains 29 reviews and more than 200 shorter contributions.
Download or read book An Introduction to Planetary Nebulae written by Jason J. Nishiyama and published by Morgan & Claypool Publishers. This book was released on 2018-05-25 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we will look at what planetary nebulae are, where they come from and where they go. We will discuss what mechanisms cause these beautiful markers of stellar demise as well as what causes them to form their variety of shapes. How we measure various aspects of planetary nebulae such as what they are made of will also be explored. Though we will give some aspects of planetary nebulae mathematical treatment, the main points should be accessible to people with only a limited background in mathematics. A short glossary of some of the more arcane astronomical terms is at the end of the book to help in understanding. Included at the end of each chapter is an extensive bibliography to the peer reviewed research on these objects and I would encourage the reader interested in an even deeper understanding to read these articles.
Download or read book Evolution of Single Stars written by Bohdan Paczyński and published by . This book was released on 1971 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Planetary Nebulae written by D.E. Osterbrock and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This written account of the Symposium on Planetary Nebulae was prepared from manuscripts submitted by the participants. Nearly every paper that was presented at the meeting is reproduced here, in either complete or abbreviated form. The dis cussions have been somewhat shortened and rearranged, but we have tried to preserve the essential points and the general tenor of the exchanges. Participants who spoke in the discussion were asked immediately for written remarks, which were then edited, reproduced, and circulated at the meeting by the highly effective local Secretariat organized by Dr Perek. In addition, notes of the discussion taken by Mrs Edith F. Swan and by the undersigned were used. We wish to thank all the authors for their unusually good cooperation. We are especially grateful to Dr Minkowski, who kindly provided many excellent repro ductions of Mount Wilson and Palomar photographs, mostly taken by himself, of various planetary nebulae. We are particularly indebted to Mrs Swan, who attended the Symposium, made notes on the papers and discussions as they occurred, and did much of the checking and editing of the manuscripts. In addition, we are very grateful to Mrs Evelyn Seaver, who also did much of the checking, editing, and retyping of manuscripts, and to Dr B.L. Webster, Miss Rebecca Todd, Mr Joseph Tapscott, and Mr Dennis Schatz, who provided excellent assistance in the preparation of this volume.
Download or read book Studies of the Nebulae written by Lick Observatory and published by . This book was released on 1918 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Formation of Planetary Nebulae with Close Binary Nuclei written by Joseph Salzman and published by . This book was released on 1978 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Temperatures of the Nuclei of Planetary Nebulae Reprinted from the Monthly Notices of the Royal Astronomical Society Vol 93 No 8 written by Richard Hugh Stoy and published by . This book was released on 1933 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Planetary Nebulae written by Silvia Torres-Peimbert and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 623 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every 5 years since 1967 a meeting has been held to discuss the subject of planetary nebulae and their central stars. Previous meetings have been held in Tatranska Lomnica (Czechoslovakia); Liege (Belgium); Ithaca, New York (U. S. A); and London (Great Britain). IAU Symposium 131 was sponsored by IAU Commision 34, on Interstellar Matter and co-sponsored by IAU Commisions 35 and 36 on Stellar Constitution and Theory of Stellar Atmospheres. The symposium was held at the Universidad Nacional Autonoma de Mexico in Mexico City, October 5-9, 1987. It took place in one of the old buildings of the University of Mexico in the downtown area. The inner patio of the building provided very pleasant surroundings for the poster sessions and for extensive discussions among the participants. The meeting was attended by 160 scientists from 22 countries. The Scientific Organizing Committee,under the chairmanship of J.B. Kaler, prepared a comprehensive scientific program based on a set of invited presentations. All contributed papers were presented in poster form. The Scientific Organizing Committee would like to thank the staff of the University of Illinois Department of Astronomy: Dr. Ron Allen for granting financial support; Carol Stickrod, Louise Browning, Deana Griffin and Sandie Osterbur for their help with the organization. IAU provided economic assistance to a group of young astronomers.
Download or read book Planetary Nebulae written by R. Weinberger and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planetary nebulae are a keystone for the understanding of the evolution of stars, for deep insights into the physical processes prevailing in highly excited dilute nebulae, and for the chemical evolution in galaxies. These objects, displaying an intriguing morphology, have a `short' lifetime of a few tens of thousands of years, and have become one of the best studied classes of celestial sources. However, despite large and successful efforts from both the observational and theoretical side, planetary nebulae still keep some of their secrets (like the widely unknown distances) and will undoubtedly also be objects of thorough investigations in the years to come.
