RANDY L. PHELPS

This is the "Sun" Module

1. For this assignment, please look through the "lecture" notes for the Sun.  These notes contain the material, in condensed form, that I will expect you to become familiar with.  I am sure you will have questions about the material, especially since it is presented in the form of lecture notes.  To help you fill in the blanks, I have added web links in the lecture notes that you can follow, in order to gain further insight into the material. 

2. Additionally, you should do the Sunspot Lab nearly every day until the specified date.  It is important that you do this exercise nearly every day!

Upon completing this assignment, you should be comfortable with the following material:

  • The important layers of the Sun, and what features occur in each.
  • The importantance of magnetic fields on the Sun.
  • How the Sun affects us here on the Earth
  • The energy processes that, historically, were thought to give rise to the energy production in the Sun.
  • What is the mechanism that gives rise to the Sun's energy, and how/why it works.
  • The sunspot cycle.

Upon completing this assignment, you should be able to answer these, and similar questions

General Concepts

  • What is meant b "helioseismology"?
  • What layer do you see when you look (carefully!) at the Sun?
  • How do sunspots relate to magnetic fields?
  • Why are sunspots dark?
  • What observation indicates that the Sun rotates differentially?
  • Why can the Sun rotate differentially?
  • Does the Sun rotate faster at its poles, or at its equator? 
  • How can one tell how quickly the Sun rotates?
  • Sunspots increase and decrease in number over what time period?
  • What regions of the Sun are considered to be the solar "atmosphere"?
  • What are solar prominences and solar flares?
  • Which are more energetic, solar flares or solar prominences?
  • Gas in the Sun's corona is very hot, which means it has high energy.   What part(s) of the electromagentic spectrum would be most useful in order to study it?
  • What are coronal holes?  How are they related to the solar wind?
  • What is the Solar wind? 
  • Why is the solar wind important to us here on the Earth?
  • What regions of the Sun are considered to be the solar "interior"?
  • Where in the Sun do thermonuclear reactions occur?
  • How do temperature and density vary as you move the center to the outer layers of the Sun?
  • How does E=mc2 tell us how energy is produced when converting Hydrogen into Helium?
  • What are the basic steps in the proton-proton chain? i.e., Understand the process by which the Sun generates energy.   Specifically know about the important reasons why it occurs, what "products" are produced and the steps that are involved.
  • Why does energy production occur in the sun? i.e., why can nuclear reactions actually occur?
  • What are the three types of energy transport?
  • What is a "dynamo"?
  • What is thought to give rise to the sunspot cycle?
  • Can charge particles move across magnetic field lines?
  • What is the "solar constant"?

Applications (review Light/Atoms from AS 4 if needed)

  • From Wien's law and the temperature of the Sun's "surface", what color should the Sun be?
  • How do Kirchoff's Laws help us to understand the structure of the Sun?
  • Sunspots have a temperature of 4200K.  If they were isolated from the solar surface, how would they appear?
  • Prominences are regions of hot, thin gas confined to magnetic field lines.  If one took a spectrum os a prominence, according to Kirchoff's Laws, what type of spectrum would you expect to observe?  As the photosphere is so bright, compared to prominences, does the first part of this question suggest a way that prominences might more easily be observed?
  • The corona is a region of thin gas, at a temperature of 2 million degrees.  In what part of the electromagnetic spectrum is the corona best studied?

These questions, and similar ones, will form the basis of  the exam material for this section of the course.  If you have problems with the material, please see me.   If you are unable to answer some of the questions, I will help you before the date specified on the syllabus, provided you show me the results of your inquiry into the material.

That is, you must provide me the answers you we able to obtain for all questions, including your attempts at problem questions, before I will help you with any of them!   

In other words, for me to provide you with help with the questions, you must show me that you have undertaken a good-faith-effort to find the answers yourself, in a timely manner.