Sections Review
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Vocabulary
color-magnitude diagram | Hertzsprung-Russell diagram |
representative sample |
spectroscopic parallax |
- How it is known that luminosity and temperature are correlated for about
90% of the stars?
- Where are luminous and faint stars plotted in the H-R diagram
(color-magnitude diagram)? Where are cool and hot stars plotted?
- Where are red giants, main sequence stars, and white dwarfs plotted in the
H-R diagram?
- Which main sequence stars are hotter and which are cooler? Which ones
are more massive and which ones are the lightweights?
- Which main sequence stars are
bigger in diameter than others? How can we tell that they are bigger?
- What is the relation between stellar luminosity and stellar mass?
- Which spectral classes are more common than others? How do you know
without having to survey the entire galaxy?
- Of the two ways of selecting stars, grouping by proximity or by
apparent brightness, which gives you a representative sample of stars?
Why is the other way a biased way of selecting stars?
- If you wanted to find an accurate proportion of the galaxies that are faint
and the proportion of the galaxies that are luminous, should you select all galaxies
within a certain volume of space of all galaxies above a certain apparent brightness?
Explain why!
- Which telescope should you use if you want to get a more accurate proportion of
faint stars to luminous stars: a 15-centimeter objective telescope or 90-centimeter
objective telescope? Explain why!
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last updated: 24 May 2001
Is this page a copy of Strobel's
Astronomy Notes?
Author of original content:
Nick Strobel