Exam 9: The Sun: Our Extraordinary Ordinary Star

Two pairs of associated sunspots appear on the visible disk of the photosphere of the Sun,one pair in each hemisphere.If the magnetic polarity of the westernmost spot in the northern hemisphere is found to be N,what will be the magnetic polarities of the other three spots?

Which astronomer was the FIRST to detect the rotation of the Sun by watching sunspot motions?

Which part of the Sun is the LEAST dense?

A hydrogen nucleus (a proton)has a charge of +1 and a helium nucleus has a charge of +2.Why,then,does it require four protons to form helium in the core of the Sun?

Which phenomeon is NOT a characteristic of the peak period in the solar activity cycle?

Which is NOT considered to be a feature of the quiet Sun?

Granulation,or the mottled appearance of the whole solar surface,is an indication of what physical process at work in the Sun?

The major feature that distinguishes a sunspot from other regions on the Sun is:

Why is the photosphere called the visible surface of the Sun? Each of the statements below is a partial answer to this question EXCEPT ONE.Which is the exception?

When we view the Sun's disk in visible light,we see less deeply into the Sun near the limb than at the center of the disk because of the interaction of the light with atoms of the gas.What conclusion can be drawn from the observation that the Sun appears less bright near the limb than it does at the disk center?

What causes plages?

How does the temperature inside the umbra of a sunspot compare with the solar photosphere outside the sunspot?

Why should you never look directly at the Sun?

What is a plage?