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Reading: Chapters 19 (The Nature of Stars) and 5 (The Nature of Light)
Normal Stars
- Mass = 0.08 to ~50-100 times the mass of the Sun
- Radius = 0.1 to ~1,000 times the radius of the Sun
- Surface Temperature = 2,500 Kelvins to 50,000-100,000 Kelvins
- Luminosity = 0.0001 to 100,000 times the luminosity of the Sun
Note that the above numbers are given in terms of the
properties of the Sun. In physical units, the properties of the Sun are:
- Mass = 2.0x10**30 kilograms
- Radius = 696,000 kilometers
- Surface Temperature = 5,800 Kelvins
- Luminosity = 3.9x10**26 Watts
The properties of normal stars span rather narrow ranges except for
their luminosities. We will also point out later, that there are several
well-defined relationships between the various stellar properties which hold
clues as to their internal structures. In this class, we will worry about:
- how these numbers were determined
- why the above numbers are what they are (and how they are related)
Let us now consider these topics We will first address how we
know things about the Sun and then generalize to other stars. We will discuss:
After these topics, we will address ways in which the general properties of
stars represented which yield clues to the fundamental nature of stars (e.g.,
the Hertzsprung-Russell, the Mass-Luminosity Rewlationship, ... )
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