Lectures on Solar Physics (Lecture Notes in Physics, 619)

✍ Scribed by H.M. Antia (editor), A. Bhatnagar (editor), Peter Ulmschneider (editor)

• Publisher: Springer
• Year: 2003
• Tongue: English
• Leaves: 231
• Edition: 2003
• Category: Library

✦ Synopsis

TheideafortheselectureseriesaroseataWorkshoponsolarphysicswhichwas heldattheInterUniversityCentreforAstronomyandAstrophysics(IUCAA), Pune/IndiainDecember2000. ThisWorkshopaimedtopresentacompreh- siveandup-to-dateoverviewofsolarphysicsforinterestedstudentsandfaculty inotherbranchesofastrophysics. Itwasintendedtoshowthatthis?eld, c- centratingonourcloseststar, isavitalandexciting?eldofresearch. Forthis purposeanumberofcomprehensivereviewswereorganisedwhichassumedthat theaudiencewouldhaveonlyabasicphysicsbackgroundbuthadnoprior knowledgeaboutsolarphysics. Thesetoflecturescoveredtopicsrangingfrom thesolarcoretotheconvectionzone, thephotosphere, chromosphere, andcorona andextendingtothesolarwindintheinterplanetarymedium DuringandaftertheWorkshoptherewasmuchenthusiasmforthisform ofpresentationanditwasfeltthattheselectures, augmentedbyincludingthe latestresearch?ndingsinthe?eld, wouldbebene?cialtoamuchlargeraudience. Thustheplanforthisbookoriginatedwhichcouldthenberealisedthanksto thepublishers, Springer-Verlag. Thereare9articlesbasedonthelecturesgivenattheWorkshop. Thearticle byChitreon"OverviewofSolarPhysics"givesanintroductiontothewhole varietyofphenomenaofsolarphysics, theproblemsandtheirsolutionsand salientresults. Thearticleon"InstrumentationandObservationaltechniques relatedtoSolarPhysics"byBhatnagardescribesindetailtheprinciplesof- larinstrumentationnormallyusedtotakesimplewhitelight, monochromatic andspectroscopicobservations. Practicalmethodstomeasureimportantbasic parameters, likearea, positionandtheclassi?cationofsunspotsaredescribed indetail. Antia'sarticleon"SolarInteriorandSeismology"describesthesolar interior, thetechniqueofhelioseismologyandhowthisnewtechniqueallowsa determinationoftheinternalstructureanddynamicsoftheSunandconstrains theoriesofstellarstructure, evolutionandangularmomentumtransport. - bastha'sarticleon"TheActiveandExplosiveSun"givesanoverviewofhighly time-dependentphenomenainthephotosphere, chromosphereandcoronaofthe Sunandprovidessometheoreticalmodelsofthesolar?ares. Hasan'sarticle on"MagneticFluxTubesandActivityontheSun"discussesthegeneration, storageandemergenceofmagnetic?eldsintheformofsmall-scale?uxtubes andexaminestheirroleinheatingofthechromosphere. Ventakrishan'sar- cleon"SolarMagneticFields"givesatheoreticaloverviewofthegeneration VI Preface ofmagnetic?eldsbythedynamomechanism, thegeneralmagnetic?eldtop- ogyandhowthemagnetic?eldsaremeasured. Ulmschneider'scontributionon "ThePhysicsofChromospheresandCoronae"discusseswhyallstarslikethe Sunhavehotouterchromosphericandcoronallayers. Itidenti?estheheating mechanismsanddynamicalprocesseswhichtakeplacebothinthepresenceand absenceofmagnetic?elds. ThearticlebyDwivedion"TheSolarCorona"gives ageneraloverviewofthesolarcorona, howitisobservedandwhatthephy- calprocessesleadingtoitsformationare. FinallyManoharan'scontributionon "TheSolarWind"describesthegenerationandmeasurementofthesolarwind derivedfrominsituobservationsbyspacecraftandinterplanetaryscintillation studies. Wehopethatbyreadingtheselectures, interestedpeople, amateurs, graduate andpostgraduatestudentswillbemotivatedtotakeupsolarphysicsasanarea ofresearch, andshareourexcitementaboutthewondersofourneareststar- theSun. WearethankfultoT. PadmanabhanandtheInterUniversityCentrefor AstronomyandAstrophysics, PunefororganisingandhostingthisWorkshop onSolarPhysics. Mumbai, Udaipur, Heidelberg H. M. Antia February2003 A. Bhatnagar P. Ulmschneider ListofContributors AshokAmbastha S. S. Hasan Udaipur Solar Observatory Indian Institute of Astrophysics Physica

✦ Table of Contents

Chapter 1
1 Introduction
2 Composition and Structure of the Sun
2.1 Equations of Stellar Structure
2.2 The Standard Solar Model
3 Probes of the Sun's Interior
3.1 Solar Neutrino Problem
3.2 Helioseismology
3.3 Rotation Rate in the Solar Interior
4 Magnetically Controlled Solar Phenomena
References
Chapter 2
1 Introduction
2 How to Observe the Sun?
2.1 Observing the Photosphere
2.2 Observation of the Chromosphere
2.3 Observation of the Corona
3 Solar Instrumentation
3.1 Solar Telescopes
3.2 Coronagraphs
3.3 Spectrographs, Spectrohelioscopes and Spectroheliographs
3.4 Narrow Band Filters
3.5 Solar Image Guider
4 Solar Observations
4.1 Solar Seeing
4.2 Sunspot Observations
4.3 Development of Sunspots and Sunspot Groups
4.4 Classification of Sunspots and Sunspot Groups
4.6 Position Determination of Solar Features
5 Solar Magnetic Fields
5.1 Sunspot Magnetic Fields
5.2 General Magnetic Fields
5.3 Velocity Field Observation
5.4 Leighton’s Spectroheliographic Technique for 2-D Velocity and Magnetic Field Maps
5.5 Vector Magnetic Fields
6 Solar Data from the Internet
Acknowledgements
References
Chapter 3
1 Introduction
2 Observations of Solar Oscillations
3 Properties of Solar Oscillations
4 Seismic Inferences of the Solar Structure
4.1 Inversion Techniques
4.2 Inversion Results
4.3 Inversion for Temperature and Chemical Composition
5 Rotation Rate in the Solar Interior
5.1 Inversion for Rotation Rate
5.2 Inversion Results
5.3 The Tachocline
5.4 Meridional Flow
6 Asphericity in Solar Structure
7 Temporal Variations in the Solar Interior
7.1 Temporal Variations of the Solar Radius
7.2 Temporal Variations of the Rotation Rate
8 Summary
Acknowledgements
References
Chapter 4
1 Introduction
2 Magnetic Fields in the Solar Interior and Flux Emergence
2.1 Solar Dynamo
2.2 Seat of the Dynamo
2.3 Flux Emergence
3 Nature of the Surface Magnetic Field
3.1 Formation of Intense Flux Tubes in the Photosphere
3.2 The Thermal Structure of Intense Flux Tubes
4 Dynamical Processes and Heating of the Magnetic Chromosphere
4.1 Longitudinal and Transverse Waves in Flux Tubes
4.2 The Linear Model
4.3 Chromospheric Heating
4.4 Nonlinear Results
5 Summary
Acknowledgements
References
Chapter 5
1 Introduction
2 Magnetohydrodynamic Approximation in Stellar Plasmas
3 Generation of Magnetic Fields
3.1 Turbulent Dynamo and Mean Field Magnetohydrodynamics
3.2 Dynamo in the Overshoot Layer
3.3 Babcock–Leighton Picture and Hybrid Models
3.4 Inputs from Helioseismology
4 Force Free Equilibria, Topology, Reconnection and Flares
5 Measurement of the Solar Magnetic Field
5.1 The Zeeman Effect
5.2 The Hanle Effect
5.3 The Stokes Parameters
5.4 Subsystems for Polarimetry
5.5 Conversion of Polarisation Maps into Magnetograms
6 Concluding Remarks
References
Chapter 6
1 Introduction
2 History of Coronal Studies
3 X-rays and Ultraviolet Emission from the Solar Atmosphere
4 Coronal Heating
4.1 Coronal Heating by Nanoflares
4.2 Coronal Heating by Waves
4.3 Fieldwork
5 Conclusions
References
Chapter 7
1 Introduction
2 The Hot Solar Corona
2.1 Coronal Magnetic Fields
2.2 Coronal Heating
3 Coronal Expansion/ Solar Wind
4 Interplanetary Magnetic Fields
5 Solar Wind Measuring Techniques
5.1 Interplanetary Scintillation
6 Solar Wind in the Inner Heliosphere
6.1 Quasi-stationary Solar Wind
6.2 Radial Evolution of the Quasi-stationary Wind
6.3 Latitudinal Variations
6.4 The Density Turbulence Spectrum
7 Solar Wind Transients
7.1 Co-rotating Interaction Regions
7.2 Coronal Mass Ejections
Acknowledgements
References