Download or read book Determination of Atmospheric Parameters of B A F and G Type Stars written by Ewa Niemczura and published by Springer. This book was released on 2014-07-10 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the theory of stellar atmospheres. Almost everything we know about stars is by analysis of the radiation coming from their atmospheres. Several aspects of astrophysics require accurate atmospheric parameters and abundances. Spectroscopy is one of the most powerful tools at an astronomer’s disposal, allowing the determination of the fundamental parameters of stars: surface temperature, gravity, chemical composition, magnetic field, rotation and turbulence. These can be supplemented by distance measurements or pulsation parameters providing information about stellar interior and stellar evolution, otherwise unavailable. The volume is based on lectures presented at the Wrocław's Spectroscopic School aimed at training young researchers in performing quantitative spectral analysis of low-, mid-, and high-resolution spectra of B, A, and F-type stars.
Download or read book The Atmospheric Parameters of Main Sequence A and F Stars written by Barry Smalley and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Spectral Evolution of Cool Helium Atmosphere White Dwarfs Detailed Spectroscopic and Photometric Analysis of DZ Stars written by and published by . This book was released on 2007 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a detailed analysis of a large spectroscopic and photometric sample of DZ white dwarfs based on our latest model atmosphere calculations. We revise the atmospheric parameters of the trigonometric parallax sample of Bergeron, Leggett, & Ruiz (12 stars) and analyze 147 new DZ white dwarfs discovered in the SDSS. The inclusion of metals and hydrogen in our model atmosphere calculations leads to different atmospheric parameters than those derived from pure helium models. Calcium abundances are found in the range from log (Ca/He) = -12 to -8. We also find that fits of the coolest objects show peculiarities, suggesting that our physical models may not correctly describe the conditions of high atmospheric pressure encountered in the coolest DZ stars. We find that the mean mass of the 11 DZ stars with trigonometric parallaxes is significantly lower than that obtained from pure helium models and in much better agreement with the mean mass of other types of white dwarfs. We determine hydrogen abundances for 27% of the DZ stars in our sample, while only upper limits are obtained for objects with low-S/N spectroscopic data. We confirm with a high level of confidence that the accretion rate of hydrogen is at least 2 orders of magnitude smaller than that of metals (and up to 5 in some cases) to be compatible with the observations. We find a correlation between the hydrogen abundance and the effective temperature, suggesting for the first time empirical evidence of a lower temperature boundary for the hydrogen screening mechanism. Finally, we speculate on the possibility that the DZA white dwarfs could be the result of the convective mixing of thin hydrogen rich atmospheres with the underlying helium convection zone.
Download or read book Determination of the Basic Physical Parameters of a Sample of Nearby Solar Type Stars written by Eric Joseph Bubar and published by . This book was released on 2005 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1969 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Rocket Propulsion written by DP Mishra and published by CRC Press. This book was released on 2017-07-20 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book follows a unified approach to present the basic principles of rocket propulsion in concise and lucid form. This textbook comprises of ten chapters ranging from brief introduction and elements of rocket propulsion, aerothermodynamics to solid, liquid and hybrid propellant rocket engines with chapter on electrical propulsion. Worked out examples are also provided at the end of chapter for understanding uncertainty analysis. This book is designed and developed as an introductory text on the fundamental aspects of rocket propulsion for both undergraduate and graduate students. It is also aimed towards practicing engineers in the field of space engineering. This comprehensive guide also provides adequate problems for audience to understand intricate aspects of rocket propulsion enabling them to design and develop rocket engines for peaceful purposes.
Download or read book Revista Mexicana de Astronom a Y Astrof sica written by and published by . This book was released on 2011 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rules of Thumb for Mechanical Engineers written by J. Edward Pope and published by Gulf Professional Publishing. This book was released on 1997 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluids -- Heat transfer -- Thermodynamics -- Mechanical seals -- Pumps and compressors -- Drivers -- Gears -- Bearings -- Piping and pressure vessels -- Tribology -- Vibration -- Materials -- Stress and strain -- Fatigue -- Instrumentation -- Engineering economics.
Download or read book Multicolor Stellar Photometry written by Vitautas Straĭzhis and published by . This book was released on 1992 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectral Classification and Multicolour Photometry written by CH. Fehrenbach and published by Springer Science & Business Media. This book was released on 2013-11-21 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr J. Landi Dessy, Director of the Astronomical Observatory, Cordoba, Argentina, invited the International Astronomical Union to hold a Symposium in Cordoba in connection with the celebration of the Centennial of the Cordoba Observatory; the date of foundation is October 24, 1871. He proposed that the Symposium should deal with Spectral Classification and Multicolour Photometry as seven years had elapsed since the Symposium No. 24 in Saltsj6baden, and much development had occurred in the field. The invitation and the proposal were accepted by the IAU, and the Symposium was held in Villa Carlos Paz, near Cordoba, between October 18 and October 24, 1971. It was attended by about 50 scientists representing Argentina, Canada, Chile, Den mark, France, Germany, Italy, Mexico, Sweden, Switzerland, U.K., U.S.A., Vatican City State and Venezuela. The Symposium was divided into four sessions: 1. Classification of slit spectra, 2. Classification of objective-prism spectra, 3. Photometric classification, 4. Catalogues and documentation. It was decided not to include problems of calibration of absolute magnitudes and temperatures of stars but to refer this to a separate symposium. The contents of the present volume follow closely the programmes of the individual sessions of the Symposium. All the participants at the Symposium appreciated the excellent hospitality of their Argentinian hosts and the efficient help given by the staff ofthe Cordoba Observatory.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1967 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Problems of Calibration of Absolute Magnitudes and Temperature of Stars written by B. Hauck and published by Springer. This book was released on 1973-10-31 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: In connection with arranging IAU Symposium No. 50 on 'Spectral Classification and Multicolour Photometry', sponsored by Commissions 45 and 25, it was decided to exclude all calibration problems. Instead it was agreed that we should attempt to arrange a separate symposium, dealing with the fundamental problems of the cali bration of absolute magnitudes and temperatures of stars. The Executive Committee of the IAU accepted our proposal, and IAU Symposium No. 54 was held in Geneva on September 12-15, 1972, sponsored by thefollowing IAU Commissions: 24, 25, 29, 33, 35, 37,44 and 45. It was attended by about 90 scientists representing 16 countries. The Symposium was divided into eight sessions. Each session started with a review paper by an invited speaker; this was followed by a general discussion including a few contributed papers. The contents of the present volume follow closely the programmes of the individual sessions of the Symposium. Most of the recorded discussions have been kept, and only in a few cases have the order of questions and comments been altered so as to obtain more homogeneity in the presentation.
Download or read book Air Pollution Engineering Manual written by Air & Waste Management Association and published by Van Nostrand Reinhold Company. This book was released on 1992 with total page 956 pages. Available in PDF, EPUB and Kindle. Book excerpt: THE AIR & WASTE MANAGEMENT ASSOCIATION is the world's leading membership organization for environmental professionals. The Association enhances the knowledge and competency of environmental professionals by providing a neutral forum for technology exchange, professional development, networking opportunities, public education, and outreach events. The Air & Waste Management Association promotes global environmental responsibility and increases the effectiveness of organizations and individuals in making critical decisions that benefit society.
Download or read book CRC Handbook of Metal Etchants written by Perrin Walker and published by CRC Press. This book was released on 1990-12-11 with total page 1434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication presents cleaning and etching solutions, their applications, and results on inorganic materials. It is a comprehensive collection of etching and cleaning solutions in a single source. Chemical formulas are presented in one of three standard formats - general, electrolytic or ionized gas formats - to insure inclusion of all necessary operational data as shown in references that accompany each numbered formula. The book describes other applications of specific solutions, including their use on other metals or metallic compounds. Physical properties, association of natural and man-made minerals, and materials are shown in relationship to crystal structure, special processing techniques and solid state devices and assemblies fabricated. This publication also presents a number of organic materials which are widely used in handling and general processing...waxes, plastics, and lacquers for example. It is useful to individuals involved in study, development, and processing of metals and metallic compounds. It is invaluable for readers from the college level to industrial R & D and full-scale device fabrication, testing and sales. Scientific disciplines, work areas and individuals with great interest include: chemistry, physics, metallurgy, geology, solid state, ceramic and glass, research libraries, individuals dealing with chemical processing of inorganic materials, societies and schools.
Download or read book Plasma Chemistry written by Alexander Fridman and published by Cambridge University Press. This book was released on 2008-05-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a fundamental introduction to all aspects of modern plasma chemistry, this book describes mechanisms and kinetics of chemical processes in plasma, plasma statistics, thermodynamics, fluid mechanics and electrodynamics, as well as all major electric discharges applied in plasma chemistry. Fridman considers most of the major applications of plasma chemistry, from electronics to thermal coatings, from treatment of polymers to fuel conversion and hydrogen production and from plasma metallurgy to plasma medicine. It is helpful to engineers, scientists and students interested in plasma physics, plasma chemistry, plasma engineering and combustion, as well as chemical physics, lasers, energy systems and environmental control. The book contains an extensive database on plasma kinetics and thermodynamics and numerical formulas for practical calculations related to specific plasma-chemical processes and applications. Problems and concept questions are provided, helpful in courses related to plasma, lasers, combustion, chemical kinetics, statistics and thermodynamics, and high-temperature and high-energy fluid mechanics.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stellar Spectral Classification written by Richard O. Gray and published by Princeton University Press. This book was released on 2021-06-08 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading experts in the field, Stellar Spectral Classification is the only book to comprehensively discuss both the foundations and most up-to-date techniques of MK and other spectral classification systems. Definitive and encyclopedic, the book introduces the astrophysics of spectroscopy, reviews the entire field of stellar astronomy, and shows how the well-tested methods of spectral classification are a powerful discovery tool for graduate students and researchers working in astronomy and astrophysics. The book begins with a historical survey, followed by chapters discussing the entire range of stellar phenomena, from brown dwarfs to supernovae. The authors account for advances in the field, including the addition of the L and T dwarf classes; the revision of the carbon star, Wolf-Rayet, and white dwarf classification schemes; and the application of neural nets to spectral classification. Copious figures illustrate the morphology of stellar spectra, and the book incorporates recent discoveries from earth-based and satellite data. Many examples of spectra are given in the red, ultraviolet, and infrared regions, as well as in the traditional blue-violet optical region, all of which are useful for researchers identifying stellar and galactic spectra. This essential reference includes a glossary, handy appendixes and tables, an index, and a Web-based resource of spectra. In addition to the authors, the contributors are Adam J. Burgasser, Margaret M. Hanson, J. Davy Kirkpatrick, and Nolan R. Walborn.
