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

Get Book Here

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.

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

Get Book Here

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.

Chromosphere-corona Transition Region

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

Get Book Here

Book Description


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

Get Book Here

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 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

Get Book Here

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.

Chromospheric Fine Structure

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

Get Book Here

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.

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

Get Book Here

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

Tables of Spectral-line Intensities

Tables of Spectral-line Intensities PDF Author: William Frederick Meggers
Publisher:
ISBN:
Category : Spectrum analysis
Languages : en
Pages : 504

Get Book Here

Book Description


Dynamics and Structure of Quiescent Solar Prominences

Dynamics and Structure of Quiescent Solar Prominences PDF Author: E.R. Priest
Publisher: Springer Science & Business Media
ISBN: 9400930771
Category : Science
Languages : en
Pages : 225

Get Book Here

Book Description
Prominences are amazing objects of great beauty whose formation, basic structure and eruption represent one of the basic unsolved problems in Solar Physics. It is now 14 years since the last book on prominences appeared (Tandberg-Hanssen, 1974), during which time much progress in our knowledge of the physics of prominences has been made, and so the time is ripe for a new text book which it is hoped will be a helpful summary of the subject for students, postdocs and solar researchers. Indeed, the last few years has seen an upsurge in interest in prominences due to high resolution ground-and space-based observations and advances in theory. For example, an IAU colloquium was held in Oslo (Jensen et al, 1978), a Solar Maximum Mission Workshop took place at Goddard Space Right Center (poland, 1986), an IAU Colloquium is planned in Yugoslavia in September 1989 in prominences and it is expected that the SOHO satellite will be a further stimulus to prominence research. In November 1987 a Workshop on the Dynamics and Structure of Solar Prominences was held in Palma Mallorca at the invitation of Jose Luis Ballester with the aim of bringing observers and theorists together and having plenty of time for in-depth discussions of the basic physics of promi nences.

Origin of Cosmic Rays

Origin of Cosmic Rays PDF Author: Vitaliĭ Lazarevich Ginzburg
Publisher:
ISBN:
Category :
Languages : en
Pages : 62

Get Book Here

Book Description


An Introduction To Solar Radiation

An Introduction To Solar Radiation PDF Author: Muhammad Iqbal
Publisher: Elsevier
ISBN: 0323151817
Category : Science
Languages : en
Pages : 409

Get Book Here

Book Description
An Introduction to Solar Radiation is an introductory text on solar radiation, with emphasis on the methods of calculation for determining the amount of solar radiation incident on a surface on the earth. Topics covered include the astronomical relationship between the sun and the earth; thermal radiation; the solar constant and its spectral distribution; and extraterrestrial solar irradiation. This book is comprised of 12 chapters and begins with an overview of the trigonometric relationships between the sun-earth line and the position of an inclined surface, followed by a discussion on the characteristics of blackbody radiation. The next chapter focuses on the solar constant and its spectral distribution, paying particular attention to extraterrestrial solar spectral irradiance and the sun's blackbody temperature. Subsequent chapters explore extraterrestrial and radiation incident on inclined planes; the optics of a cloudless-sky atmosphere; solar spectral radiation and total (broadband) radiation under cloudless skies; and solar radiation arriving at horizontal surfaces on the earth through cloudy skies. The ground albedo and its spectral and angular variation are also described, along with insolation on inclined surfaces. The last chapter is devoted to instruments for measuring solar radiation, including pyrheliometers and pyranometers. This monograph will serve as a useful guide for energy analysts, designers of thermal devices, architects and engineers, agronomists, and hydrologists as well as senior graduate students.