1. Unit 2: Lesson 5- Classifying stars SWBAT: Plot and analyze stars according to their temperature and luminosity. WOD: main sequence star- hot luminous star during the longest stage of its life. Our sun is a main sequence star. Initial Activity: Why do you think some stars in the sky are brighter then others? Write down the reasons you think would make a star more or less bright. Mini Lesson: How can the HR diagram be used to analyze stars in relation to our sun? Activity: Lab groups- Lab #6- analyzing the HR diagram Summary: How can this diagram help us understand the relationship between temperature and luminosity?

2. How are stars classified? Stars are classified according to their luminosity and temperature. Luminosity: measurement of how bright a star shines. ◦Brighter stars are more luminous then dimmer stars. ◦The larger a star is the more luminous it is.  Which of these stars is the most luminous?  2 nd most?

3. Colors of Stars The color of a star is directly related to its temperature. Stars can be blue, white, yellow, or red depending on how hot they are.

4. We will discover through this lab how temperature affects luminosity of a star: Today you will only complete steps 1 & 2 of the procedure  You will plot points on a graph called the Hertzsprung- Russell Diagram Use a point to represent each star and label the point with the stars name. Exit ticket: Copy the question and circle the correct answer on your weekly exit ticket sheet. Compared to our sun, the star Betelgeuse is 1.smaller, hotter, and less luminous 2.Smaller, cooler, and more luminous 3.Larger, hotter, and less luminous 4.Larger, cooler, and more luminous