Solar and Stellar Magnetic Fields: Origins and Coronal Effects / Edition 1

by Jan Olof Stenflo

Overview

Traditionally, solar and stellar physics have been two separate branches of astronomy, which independently of each other have developed their own scientific goals and methods. During the last decade, however, we have witnessed a gradual convergence of these two areas: The solar physicists realize more and more that the sun has to be seen as a special case in a large family of stars of various properties. A more complete understanding of the sun can only be achieved by considering it in this broader context. The stellar physicists on the other hand have become aware that the detailed knowledge of the physical processes that the solar physicists have reached has a more general significance and can be applied to a variety of other astrophysical objects. Observational techniques developed in solar work can frequently be adapted for other stars as well. This unified approach to solar and stellar physics is often called the "solar-stellar connection". One main goal of this approach has been to understand the general nature and causes of stellar activity. The pioneering and visionary program to search for activity cycles on other stars started by Olin Wilson at the Mount Wilson Observatory 16 years ago has born fruit: in his sample of 91 stars, cyclic behaviour similar to that of the sun is found to be quite common, but many stars also show irregular activity fluctua.tions of large amplitude.

Product Details

ISBN-13:	9789027716217
Publisher:	Springer Netherlands
Publication date:	07/31/1983
Series:	International Astronomical Union Symposia , #102
Edition description:	Softcover reprint of the original 1st ed. 1983
Pages:	564
Product dimensions:	6.90(w) x 10.00(h) x 1.40(d)

Table of Contents

I. Magnetic Fields in Stellar Photospheres.- Observations of Magnetic Fields on Late-type Stars.- Long-term Coherent Periodicities in the Mean Magnetic Field of the Sun.- Methods and Results for Detecting Magnetic Fields on Late-type Stars.- Zeeman Effect Observations in the RS CVn Star HR 5110 and in Late-type Stars with Strong Ca II Emission.- Theory of Photospheric Magnetic Fields.- Solitons in Magnetic Flux Tubes.- Self-consistent Models for Small Photospheric Flux Tubes.- Time-dependent Convective Collapse of Flux Tubes.- Numerical 3-D Simulations of the Collapse of Photospheric Flux Tubes.- Chromospheric and Coronal Indicators of Stellar Magnetic Structure.- II. Rotation — Activity — Cycle — Age Connection: Observations.- The Observed Relationships between Some Solar Rotation Parameters and the Activity Cycle.- The Mount Wilson Program for Stellar Activity Cycles.- The Relation between Rotation and Magnetic Activity on Lower Main Sequence Stars as Derived from Chromospheric Indicators.- Magnetic Fields and Convection: New Observations.- Possibilities and Attempts to Determine the Differential Rotation on F-type Main-sequence Stars.- IUE Observations of the Chromospheric Activity-Age Relation in Young Solar-type Stars.- Stellar X-ray Emission as an Indicator of Stellar Magnetic Activity.- Fractional Stellar Convection Zone Depth and the Generation of Magnetic Flux: An Empirical Approach.- The Coronal Rotation-Activity Relations in Late-type Stars.- Period-Activity Relations in Close Binary Systems.- Coronal Activity in F-, G-, and K-type Stars; Empirical Relations between Stellar Parameters.- III. Theory of Stellar Magnetic Field Generation.- Stellar Dynamo Theory.- A Molecular Weight Gradient Battery Mechanism for Stellar Magnetic Fields.- TopologicalMagnetic Flux Pumping Revisited.- Dynamos of the Sun and Stars, and Associated Convection Zone Dynamics.- Helical and Non-helical Dynamos.- A Quantitative Study of Magnetic Flux Transport on the Sun.- On the Stellar Rotation-Activity Connection.- Amplification of Magnetic Fields by Compressible Convection.- Periodic and Aperiodic Behaviour in Stellar Dynamos.- IV. The Role of Magnetic Fields in the Structure and Energy Balance of Stellar Atmospheres.- The Role of Magnetic Fields in Stellar Chromospheres and Transition Regions.- The Magnetic Field Configuration in Solar and Stellar Chromospheres.- Empirical Scaling Laws for Coronal Heating.- Radio Wavelength Observations: Structure, Strength and Variability of Magnetic Fields in the Transition Region and the Solar Corona.- Coronal and Chromospheric Structures in AR Lac: I. Data and Models.- The Role of Magnetic Fields in the Heating of Stellar Atmospheres — Theory.- VLA Observations of Quiescent and Flare Microwave Emission from Late-type Stars: A Unique Probe of Coronal Magnetic Fields.- Electrodynamic Coupling in Magnetically Confined Stellar X-ray Loops.- A Thermal Catastrophe in a Resonantly Heated Coronal Loop.- Finite Amplitude Effects of Torsional Alfvén Waves in a Flux Tube.- Observations of Alfvén Waves Simultaneously in H? and K.- Heating of Intense Magnetic Flux Tubes by Magnetohydrodynamic Waves.- V. Stellar Winds and Spindown in Late-Type Stars.- Stellar Winds and Spindown — Observations.- Angular Momentum Loss and Chromospheric Activity in Late-type Dwarfs.- Magnetic Topology and the Heating of Extended Chromospheres.- Stellar Winds and Spindown in Solar Type Stars.- The Remarkable Rotational Braking of G5 Giants.- Expulsion of Magnetized Plasmas from Coronae.- Plasma Flow and Solar WindAcceleration in Non-radial Coronal Magnetic Fields.- Magnetic Braking and Angular Momenta of Protostars.- Closed and Open Magnetic Fields in Stellar Atmospheres: Effects on Mass Loss from Cool Giant Stars.- Stellar Winds and Spindown in Red Giants.- VI. Summary and Future Directions.- Observational Needs for Progress in Solar/Stellar Magnetic Activity: Overview.- Observational Requirements: Ground-based.- Outlook for Ground-based and Space Observations.- Theoretical Problems.- Relationships between Solar and Stellar Magnetic Fields.- List of Poster Papers.- List of Participants.- Author Index.