Notes
Outline
The Small Angle Approx-imation
Measuring distance with triangulation
Parallax – direct distances to the stars
The Luminosity Law
The Inverse-Square Law
Observation of stellar properties
Energy Levels in Atoms
Energy transitions and photons
Unique Atomic Signatures
Astro Quiz
The spacing between 2 levels in the first atom must be twice the spacing between 2 levels in the second atom.
The spacing between 2 levels in the first atom must be half  the spacing between 2 levels in the second atom.
The energy of the upper of 2 levels in the first atom must be half that of the energy of the upper of 2 levels in the second atom.
Transitions in Hydrogen
Spectrometers
Diffraction gratings
The Solar Spectrum
Stellar Spectral Types
Decoding Stellar Spectra
Properties of the Spectral Types
The Brightest and Nearest Stars
Towards the “HR diagram”
The Hertzsprung-Russell Diagram
Basics of the HR diagram
Size/Luminosity