Fall 2000 ASTR 1120-001 Review for Quiz 2
The quiz will contain 10 multiple-choice questions,
and will be 10 minutes long.
The intention is that all material on the quiz
(saving matters of logic and common sense)
is referred to somewhere here.
Review the worksheet on Temperature.
What is absolute temperature?
What is the conversion factor between energy and Kelvin?
What is absolute zero?
When can an object be described by a temperature?
What is thermodynamic equilibrium?
What is the spectrum of an object in thermodynamic equilibrium called?
What is Wien's Law?
What is the Stefan-Boltzmann Law?
If a gravitating system loses energy, does it cool down
(decrease temperature) or heat up (increase temperature)?
Give one or more examples where this happens in astronomy.
What is a plasma?
Under what conditions does matter become a plasma?
What profound new idea did Eddington have about the condition of matter
inside the Sun that revolutionized our concept of the Sun?
How did Eddington estimate the temperature at the center of the Sun?
For a description of his ideas in his own words,
Eddington's 1920 Address.
Bennett calls this `gravitational equilibrium'.
What is hydrostatic equilibrium?
Is the Sun in hydrostatic equilibrium?
What is the source of the Sun's energy?
Back at the beginning of the 20th century,
a leading theory was Kelvin's suggestion that the Sun was
powered by its own gravitational contraction?
What was wrong with that theory?
Has the Sun ever been powered by gravitational contraction?
Give an account of the fusion of hydrogen to helium in the Sun.
Where does the energy come from?
Why doesn't the Sun explode like a nuclear bomb?
What are the 2 essential ingredients of a bomb?
What is the
What is a redshift? Blueshift?
What is helioseismology?
What do astronomers learn from helioseismology?
To find out more,
visit the superb
Helio- and Asteroseismology
site at the Institute for Physics and Astronomy, Aarhus University,
Describe the Sun's spectrum.
What are Fraunhofer (1814) lines?
Explain why the Sun's spectrum looks the way it does.
What is it possible to learn from the spectrum of the Sun?
What are Henry Draper, Annie Jump Cannon, and Cecilia Payne-Gaposchkin
What is spectral type?
What has temperature got to do with spectral type?
What is the sequence of spectral types?
Ha in stars.
In what spectral type of star is the
Is the line in absorption or emission?
Draw an atomic energy level diagram of H showing the
Sketch a graph showing how the strength of the
line varies with temperature.
Explain physically why the
line varies with temperature the way it does.