Chapter 17

Suppose the rate at which deuterons react with protons to form \(^{3}\) He in the Sun's core were twice as fast as it actually is. What effect would such a difference make in the rate at which the Sun's hydrogen is converted into helium?

Why does it take so long for the energy produced in the Sun's core to reach the surface?

Suppose the Sun's nuclear reactions were to drop by \(50 \%\) next Sunday and resume their normal rate again the following Saturday. How noticeable would this temporary drop in energy production be when the energy produced next week finally reaches the Sun's surface?

Explain why the solar neutrino telescope in South Dakota is located 1 mile beneath the Earth's surface and why it can operate around the clock.

Suppose the density of gas in the Sun's photosphere fell much less rapidly with increasing distance from the center than it really does. What effect would this have on the sharpness of the Sun's limb?

Suppose the Sun's limb were brighter than the center of the Sun's disk. What would that tell us about the temperature structure of the Sun's photosphere?

Describe a spicule.

Why was it difficult for astronomers to identify the elements responsible for the emission lines radiated by the corona?

What is the relationship between coronal holes and the solar wind?

Why does the magnetic field of the solar wind follow a spiral pattern?

What does a butterfly diagram tell us about the numbers and locations of sunspots during a sunspot cycle?