The Solar Transition Region

The Solar Transition Region PDF Author: John T. Mariska
Publisher: Cambridge University Press
ISBN: 9780521382618
Category : Science
Languages : en
Pages : 308

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Book Description
The solar transition region, which spans the temperature range from about 20,000 to 1,000,000 K, separates the chromosphere from the corona. All the energy that heats the corona and powers the solar wind must pass through this part of the solar atmosphere. This book summarizes recent ultraviolet and extreme ultraviolet observations of the transition region, the empirical models derived from them, and the physical models that try to explain both the observations and the empirical models. The observational focus is on quiet solar transition region observations made with Skylab and subsequent rocket and satellite experiments. The book also presents a unified discussion of the analysis of ultraviolet and extreme ultraviolet spectroscopic data, including the determination of the emission measure and density and temperature diagnostics. This will be useful to astrophysicists who are confronting high-resolution ultraviolet and extreme ultraviolet data from astrophysical plasmas for the first time.

The Solar Transition Region

The Solar Transition Region PDF Author: John T. Mariska
Publisher: Cambridge University Press
ISBN: 9780521382618
Category : Science
Languages : en
Pages : 308

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Book Description
The solar transition region, which spans the temperature range from about 20,000 to 1,000,000 K, separates the chromosphere from the corona. All the energy that heats the corona and powers the solar wind must pass through this part of the solar atmosphere. This book summarizes recent ultraviolet and extreme ultraviolet observations of the transition region, the empirical models derived from them, and the physical models that try to explain both the observations and the empirical models. The observational focus is on quiet solar transition region observations made with Skylab and subsequent rocket and satellite experiments. The book also presents a unified discussion of the analysis of ultraviolet and extreme ultraviolet spectroscopic data, including the determination of the emission measure and density and temperature diagnostics. This will be useful to astrophysicists who are confronting high-resolution ultraviolet and extreme ultraviolet data from astrophysical plasmas for the first time.

Solar Composition and its Evolution — from Core to Corona

Solar Composition and its Evolution — from Core to Corona PDF Author: Claus Fröhlich
Publisher: Springer Science & Business Media
ISBN: 9401148201
Category : Science
Languages : en
Pages : 438

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Book Description
The discovery of chemical elements in celestial bodies and the first estimates of the chemical composition of the solar atmosphere were early results of Astrophysics - the subdiscipline of Astronomy that was originally concerned with the general laws of radiation and with spectroscopy. Following the initial quantitative abundance studies by Henry Norris Russell and by Cecilia Payne-Gaposchkin, a tremendous amount of theoretical, observa tional, laboratory and computational work led to a steadily improving body of knowledge of photospheric abundances - a body of knowledge that served to guide the theory of stellar evolution. Solar abundances determined from photospheric spectra, together with the very similar abundances determined from carbonaceous chondrites (where extensive information on isotopic composition is available as well), are nowadays the reference for all cosmic composition measures. Early astrophysical studies of the solar photospheric composition made use of atmosphere models and atomic data. Consistent abundances derived from different atmospheric layers and from lines of different strength helped to confirm and estab lish both models and atomic data, and eventually led to the now accepted, so-called "absolute" abundance values - which, for practical reasons, however, are usually given relative to the number of hydrogen nuclei.

The Solar Chromosphere and Corona: Quiet Sun

The Solar Chromosphere and Corona: Quiet Sun PDF Author: R.G. Athay
Publisher: Springer Science & Business Media
ISBN: 9401017158
Category : Science
Languages : en
Pages : 517

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Book Description
The widespread tendency in solar physics to divide the solar atmosphere into separate layers and to distinguish phenomena of solar activity from phenomena of the quiet Sun emphasizes the wide ranging diversity of physical conditions and events occurring in the solar atmosphere. This diversity spans the range from a neutral, essentially quiescent atmosphere to a highly ionized, violently convective atmosphere; from a domain in which magnetic field effects are unimportant to a domain in which the magnetic pressure exceeds the gas pressure, and from a domain in which the particle motions are Maxwellian to a domain in which an appreciable fraction of the particles is accelerated to relativistic energies. It is now widely recognized that the chromosphere and corona have a common origin in the mechanical energy flux generated in the hydrogen convection zone lying beneath the photosphere. Furthermore, magnetic field phenomena appear to be as vital to the structure of th~ quiet Sun as to the active Sun. For these reasons it appears desirable to present a unified treatment of the entire solar atmosphere, both active and quiet, in a single volume. On the other hand, such a treatise must be very long if it is to avoid being superficial, and it is very difficult for a single author to write authoritatively on such a wide range of topics.

Chromosphere-corona Transition Region

Chromosphere-corona Transition Region PDF Author:
Publisher:
ISBN:
Category : Solar chromosphere
Languages : en
Pages : 372

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Book Description


The Structure of the Sun

The Structure of the Sun PDF Author: T. Roca Cortes
Publisher: Cambridge University Press
ISBN: 9780521563079
Category : Science
Languages : en
Pages : 422

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Book Description
The complex internal structure of the Sun can now be studied in detail through helioseismology and neutrino astronomy. The VI Canary Islands Winter School of Astrophysics was dedicated to examining these powerful new techniques. Based on this meeting, eight specially-written chapters by world-experts are presented in this timely volume. We are shown how the internal composition and dynamical structure of the Sun can be deduced through helioseismology; and how the central temperature can be determined from the flux of solar neutrinos. This volume provides an excellent introduction for graduate students and an up-to-date overview for researchers working on the Sun, neutrino astronomy and helio- and asteroseismology.

The Sun as a Guide to Stellar Physics

The Sun as a Guide to Stellar Physics PDF Author: Oddbjørn Engvold
Publisher: Elsevier
ISBN: 0128143355
Category : Science
Languages : en
Pages : 524

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Book Description
The Sun as a Guide to Stellar Physics illustrates the significance of the Sun in understanding stars through anexamination of the discoveries and insights gained from solar physics research. Ranging from theories to modelingand from numerical simulations to instrumentation and data processing, the book provides an overview of whatwe currently understand and how the Sun can be a model for gaining further knowledge about stellar physics.Providing both updates on recent developments in solar physics and applications to stellar physics, this bookstrengthens the solar–stellar connection and summarizes what we know about the Sun for the stellar, space, andgeophysics communities. - Applies observations, theoretical understanding, modeling capabilities and physical processes first revealed by the sun to the study of stellar physics - Illustrates how studies of Proxima Solaris have led to progress in space science, stellar physics and related fields - Uses characteristics of solar phenomena as a guide for understanding the physics of stars

Astrophysical Spectropolarimetry

Astrophysical Spectropolarimetry PDF Author: J. Trujillo-Bueno
Publisher: Cambridge University Press
ISBN: 0521809983
Category : Science
Languages : en
Pages : 372

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Book Description
The polarization of light is the key to obtaining a wealth of essential information that lies encoded in the electromagnetic radiation from cosmic objects. Spectropolarimetry and imaging polarimetry provide powerful diagnostics of the physical conditions in astrophysical plasmas, which cannot be obtained via conventional spectroscopy. Whilst its application to other fields of astrophysics is still at an early stage of development, spectropolarimetry is being used with great success in solar physics. The book contains the lectures delivered at the XII Canary Islands Winter School of Astrophysics. Written by eight prestigious astrophysics researchers, it covers the physics of polarization, polarized radiation diagnostics of solar magnetic fields, stellar magnetic fields, polarization insights for active galactic nuclei, compact objects and accretion disks, astronomical masers and their polarization, infrared-submillimeter spectropolarimetry, and instrumentation for astrophysical spectropolarimetry. This timely volume will provide graduate students and researchers with an unprecedented introduction to the field of Astrophysical Spectropolarimetry.

Chromospheric Fine Structure

Chromospheric Fine Structure PDF Author: R.G. Athay
Publisher: Springer Science & Business Media
ISBN: 9401021031
Category : Science
Languages : en
Pages : 296

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Book Description
The devotion of an IA U symposium entirely to the topic of chromo spheric fine structure at a time when models of the spherically symmetric chromosphere are still evolving constitutes a valid recognition of the growing feeling among solar astron omers that the chromosphere cannot be understood independently of its discrete structural features. Network structure, which seemingly borders the photospheric supergranule cells, persists intact throughout the chromosphere and most of the chromosphere-corona transition region. The network is the locus of the bright coarse mottles, and the spicule bushes and is the terminus for one end of the quiet chromo spheric fibrils as well. Additionally, it is the locus of most of the magnetic flux of the quiet chromosphere. It is not surprising, therefore, that current studies of the chromosphere tend to center around efforts to better describe the network phenom ena and to ascertain the physical properties of the network features. Clearly, the supergranule cells and associated network structures constitute a fundamental and singularly important feature of solar structure in the boundary layers. Just as it is now clear that much of the chromo spheric fine structure is associated with the network bordering supergranule cells, it seems equally clear that structural features are almost universally associated with both fluid flow and magnetic geometry. Indeed, many observers claim that the brightness features faithfully map the mag netic lines offorce while still others claim that associated with each class of brightness feature there is a more or less unique fluid flow.

Literature 1987, Part 1

Literature 1987, Part 1 PDF Author: S. Böhme
Publisher: Springer Science & Business Media
ISBN: 3662123584
Category : Science
Languages : en
Pages : 1300

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Book Description
Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 43 records literature published in 1987 and received before August 15, 1987. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Beate Gobel, Ms. Monika Kohl, Ms. Sylvia Matyssek, Ms. Doris Schmitz-Braunstein, Ms. Utta-Barbara Stegemann. Mr. Jochen Heidt and Mr. Kristopher Polzine supported our task by careful proof reading. It is a pleasure to thank them all for their encouragement. Heidelberg, October 1987 The Editors Contents Introduction . . . . . . . . . . . 1 Concordance Relation: PHYS-AAA 3 Abbreviations 5 Periodicals, Proceedings, Books, Activities 001 Periodicals . . . . . . . . . . . 10 002 Bibliographical Publications, Documentation, Catalogues, Data Bases 50 003 Books ...... .

Nuclear Science Abstracts

Nuclear Science Abstracts PDF Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1216

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Book Description