Astronomy Notes

Part 10: Basic Properties of Stars

John P. Pratt

Visual Observations

Names

Looking at Stars

Photographs of Stars

Distances

Apparent Brightness of Stars

Measuring Properties of Stars

Absolute Magnitude

Spectra

Spectral Class Facts Worth Memorizing
ColorSpectral Class Temperature (K)Absorption Lines Example Stars
BlueO30,000Ionized HeliumOrion's Belt
BlueB18,000HeliumSpica
Blue-WhiteA10,000Hydrogen (thick lines)Sirius, Rigel
WhiteF7,000Hydrogen (thin lines)Procyon
YellowG5,500Ionized MetalsSun, Capella
OrangeK4,000Neutral MetalsArcturus
RedM3,000MoleculesAntares, Betelgeuse

The Doppler Shift

Measuring Distances to Stars

Luminosity and the Stefan-Boltzman Law

Stellar Diameters

Stellar Masses