Spectroscopy: the Key to the Stars: Reading the Lines in Stellar Spectra Book

Introduction     xi
Spectroscopy-A New Golden Age for Amateur Astronomy     1
The Basic Stuff-Light Radiation and Atoms     5
Light     5
Electromagnetic Radiation     11
Atoms     19
Summary     21
Behind the Lines-The Magnificent Energy Level Structure of an Atom     23
Energy Levels     23
Electron Transitions     26
It All Comes Down to the (Quantum) Numbers     31
The Rules of the Game-Selection Rules     34
Order from Chaos-Spectral Series     35
Dancing Electrons-It Takes Two (or More) to Tango     38
Ions     41
A Final but Very Important Note     42
Summary     42
Our Old Friend the Doppler Effect     45
Waves and Movement     45
How It Works     46
The Relativistic Doppler Shift     47
A Very Important Point     48
Summary     50
When Is a Spectral Line Not a Spectral Line?     51
Line Profiles     51
Equivalent Width     52
Populations of Atoms     54
Shivering Energy Levels     55
Enter the DopplerEffect     57
Turbulence     60
Piling the Pressure On     61
Convolutions     61
How Broad Is a Line Profile?     63
Summary     68
Stellar Spectra and That Famous Mnemonic     69
Stellar Atmospheres     69
Continuous Absorption     70
Line Absorption     72
The Spectral Sequence     75
Line Broadening     78
Spectral Snapshots     79
A Word or Two About the Herzsprung-Russell Diagram     80
Summary     81
Cool but not Smooth-The Molecular Spectra of Red Stars     83
Stellar Atmosphere Versus the Chemistry Lab     84
The Things That Molecules Do     84
Summary     91
Glows in the Dark-Emission Lines and Nebulae     93
What Comes Down Must First Go Up     93
Recombination     95
Photon Degrading and Recycling     96
Thick and Thin Nebulae     97
Yet More Photon Recycling-Fluorescence     100
Forbidden Radiation     100
The Edge of a Nebula     102
Summary     102
Glowing Vortices-Accretion Disks      105
Astrophysical Modelling     105
Anatomy of an Accretion Disk     106
Building the Model     107
A Better Model     113
Thinking Up an Even Better Model     115
Summary     117
The P Cygni Profile and Friends     119
The Classic P Cygni Profile     119
Wind Outflow Geometry     120
P Cygni Profiles from Cool Stars     121
A P Cygni Profile Mystery-Symbiotic Stars     122
Summary     125
Spectral Magnetism-The Zeeman Effect     127
How Strong Is a Magnetic Field?     127
More on Electrons in Atoms     128
Momentum     128
Angular Momentum     129
The Wonderful World of x y z     130
Enter the Magnetic Field     131
Electron Transitions in a Magnetic Field     134
Looking Straight Down the Magnetic Field     136
How Wide Do the Lines Get Split?     138
Complex Atoms     139
Very Strong Magnetic Fields     139
Summary     140
'How Much Gold in Them There Stars?'-The Curve of Growth     141
Abundances     141
A Laboratory Experiment      142
A Bit of Theory     143
Another Bit of Theory     145
Determining Abundances     147
Summary     148
Conclusion     149
Powers of Ten     151
Constants and Formulae     155
Physical Constants     155
Astronomical Constants     156
Formulae     156
Index     159