Michael A. Harris
1st Lesson Plan
Stellar Evolution Day 1
Learning Objectives (At the end of this lesson my students will…)
Be able to explain how stars are formed.
Be able to describe the life cycles of medium-sized and massive stars and discuss current scientific ideas about black holes.
Materials
Homework Assignment: Readings and H-R diagram example
Poster paper
Markers/Crayons
Textbook
Star charts
Learning Activities
Prior to starting the lessons on stellar evolution the students will be assigned homework involving readings from the textbook and from any current articles available at the time. Begin the lessons on stellar evolution with an open discussion to answer any of their questions from the readings, and provide a basic overview of stellar evolution and how mass determines a star's evolutionary track. Use questioning to assess their understanding of the topic.
Continue the lesson with a group activity. Assign the students to groups that match up lower performing students with higher performing students. This will facilitate complete classroom learning. Create 5 to 6 groups of no more than four students per group. Give each group the name of a star and have the students use their textbook to look up the mass of that star. (Note: make sure that you provide different groups with stars of different masses. The goal is to show how a star's mass determines how it will evolve.)
Have the students determine the mass and then determine how the star will evolve based on the current information. For example if it is a low mass star, the students should find that the star would evolve from a main sequence to a red giant and then to a white dwarf. However, the groups that are given an intermediate or high mass star should show that the star would take a different evolutionary track.
Each group will be responsible for determining the evolutionary track of their star, writing a short essay describing the different stages, illustrating each stage, and finally presenting this information to the class. The presentations will take place during the second class period.
Lesson Closure (Assess their understanding)
Questioning
Homework: The Evolution of StarsInterpreting a Diagram
Reflection Time
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2nd Lesson Plan
Star Evolution Day 2
Learning Objectives (At the end of this lesson my students will…)
Be able to define and describe the Hertzsprung-Russell diagram.
Be able to plot a star on the H-R diagram.
Be able to determine a star's temperature, color, luminosity, and current stage of evolution from reading a H-R diagram.
Be able to make a data table and graph such data.
Materials
Graphing paper
Ruler
Copies of H-R diagrams (without stars plotted on it)
Learning Activities
The second lesson will involve science process skills such as classifying, making a data table, and graphing. As homework from the previous lesson, the students will read about the H-R diagram and be asked to review star characteristics from an earlier unit.
Start the lesson with a discussion of the homework and an introduction to the H-R diagram. Discuss luminosity, temperature, and color. Show the students how color and temperature are related. Using an overhead projector, demonstrate how knowing a stars temperature and luminosity, one can plot it position on the H-R diagram. And from plotting the star one can determine the star's current point in its evolution. Once it is determined that the student understand the H-R diagram and how to plot a star on such a graph, give the students the names of two stars and also have them choose two stars from the appendix in their textbook.
Next have each student work independently to create data tables showing the star's name, mass, temperature, color, luminosity, and current point of evolution (main sequence, red giant, white dwarf, etc.). The students will then use this data to plot the star on the H-R diagram. End the class with a review of the sun's characteristics and location on the H-R diagram. Get the students to start thinking about how the sun will evolve. This will help lead into the next lesson that deals with the fate of life on Earth as the sun completes its evolution.
Lesson Closure (Assess their understanding)
Questioning to assess understanding and do a quick review of the sun's characteristics and location on the H-R diagram. Get the students to start thinking about how the sun will evolve. This will help lead into the next lesson that deals with the fate of life on Earth as the sun completes its evolution.
Reflection Time
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3rd Lesson Plan
The Sun's Evolution and the Fate of Earth
Learning Objectives (At the end of this lesson my students will…)
Be able to describe the sun's characteristics such as temperature, color, and luminosity.
Be able to describe how the sun will evolve based on its initial mass.
Be able to describe how such an evolution will affect life on Earth.
Be able to write a informative letter about the fate of life on Earth as the sun evolves.
Materials
Poster Paper
Markers/crayons
Learning Activities
The third lesson will involve the students determining the mass of the sun, its age, and its position on the H-R diagram. Have the students locate the sun on the H-R diagram and determine the current luminosity, color, and temperature. Also have them note that the sun is located along the main sequence section of the graph. On an overhead projector, make a data table that shows the aforementioned characteristics as well as the sun's mass.
Start a discussion to review how a stars mass determines it's evolutionary path. Discuss with the class the age of the sun and how much longer it will continue to burn its fuel. Continue the discussion to determine as a class how the sun will evolve. Remind the students that they will be writing a letter to inform others of the fate of life on Earth. It is a good idea to have a student draw the stages on the board as the class discusses each stage. For example, every star begins as a giant molecule cloud, so have the student draw that stage first. Then have the student draw the protosun stage.
As the student begins to draw the main sequence stage, inform him/her that you want them to draw in the planets. Have the students explain what happens during the red giant stage. You can provide them with the figures for the distance that the outer hydrogen shell will expand to. They should be able to make the connection that the distance is close to the distance between the sun and Earth. Also discuss how the luminosity increases and the amount of radiation increases. Finally, relate the increase in the radiation and luminosity to the fate of life on Earth. Have the student write a letter describing these affects and how long it will take before this happens.
Lesson Closure (Assess their understanding)
Questioning to assess understanding.
Reflection Time
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