Objectives (5 - 10 minutes)

1. Understanding the life cycle of stars, including birth, life, and death, with special emphasis on the evolutionary cycle of the Sun.
2. Identification and analysis of possible endings of a star, focusing on the process of supernova formation.
3. Developing the ability to observe and interpret graphs and diagrams related to stellar evolution.

Secondary Objectives:

1. Stimulating critical thinking and curiosity of students about the universe and astronomical phenomena.
2. Promoting classroom discussion, encouraging students to share their prior knowledge and hypotheses on the subject.
3. Fostering individual and group research as a tool for autonomous learning.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher should start the lesson with a quick review of previously learned concepts that are essential for understanding stellar evolution, such as star formation from nebulae and the basic composition of stars. Additionally, it may be useful to review physics concepts, such as nuclear fusion.

2. Problem situations: The teacher can present two situations to arouse students' curiosity:

   • 'If all the stars in the universe eventually die, what will happen to our Sun?'
   • 'What happens to a star when it dies and why do some of them become supernovae?'

3. Contextualization: The teacher can contextualize the importance of studying stars by explaining how understanding stellar evolution contributes to our comprehension of the universe. They can mention how the death of stars and the formation of supernovae contribute to the creation of heavier chemical elements that are essential for life.

4. Capturing students' attention: The teacher can start the lesson with two curiosities:

   • 'Did you know that our Sun is a medium-sized star and that there are stars in the universe that are thousands of times larger than our Sun?'
   • 'Did you know that a supernova is such a bright explosion that, for a short period, it can outshine its host galaxy, which contains hundreds of billions of stars?'

5. Introduction to the topic: The teacher should then introduce the lesson topic - the evolution of stars - explaining that they will learn about the life cycle of stars, including birth, life, and death, and that they will analyze the evolutionary cycle of the Sun and other stars.

6. Lesson objectives: Finally, the teacher should explain the lesson objectives and what is expected for students to learn by the end of it.

Development (20 - 25 minutes)

Activity 1: Simulation of the life cycle of a star (10 - 12 minutes)

1. The teacher will divide the students into groups of 3 to 4 members and distribute to each group a cardboard sheet, colored markers, glue, glitter, and cotton.
2. The teacher will explain that each group should create a simulation of the life cycle of a star, from its birth to its death, using the provided materials.
3. The teacher will provide a step-by-step guide describing the different stages of a star's life that students should follow to create their simulation.
4. Students should work together to create their simulation, discussing and deciding how to represent each stage of the star's life cycle.
5. At the end of the activity, each group will present their simulation to the class, explaining each stage of the star's life cycle they represented.

Activity 2: Debate on the fate of the Sun (10 - 13 minutes)

1. The teacher will divide the class into two groups and propose a debate on the following topic: 'What will happen to our Sun?'
2. One group will represent the position that the Sun will turn into a supernova, while the other group will argue that the Sun will turn into a white dwarf.
3. The teacher will provide each group with a list of key points to help shape their arguments and will guide students to do quick research on their smartphones or tablets to find additional information to support their positions.
4. Each group will have a set time to present their arguments, followed by a round of questions and answers and an opportunity for a rebuttal.
5. At the end of the debate, the teacher will summarize the main points presented by each group and explain what will actually happen to the Sun, based on current scientific knowledge.

Activity 3: Creating a Supernova in a Bottle (optional, if time and resources allow) (5 - 10 minutes)

1. The teacher will ask students to gather in groups of 3 to 4. Each group will receive a transparent plastic bottle, water, glitter in various colors, and effervescent tablets.
2. The teacher will explain that the activity consists of simulating a supernova in a bottle. The water will represent space, the glitter the stars, and the effervescent tablets the supernova explosion.
3. Students will fill the bottle with water to about 3/4 of its capacity. Then, they will add the glitter and, lastly, the effervescent tablets.
4. The teacher will explain that the effervescent reaction symbolizes the explosion of a supernova, releasing elements into space, represented by the dispersion of glitter in the water.
5. At the end of the activity, the teacher will reinforce the idea that supernovae are essential in spreading heavy elements in the universe, elements that are necessary for the formation of planets and life.

Return (10 - 15 minutes)

1. Group discussion (5 - 7 minutes)

   • The teacher should gather all students for a group discussion on the conclusions each group reached during the activities. Each group will have the opportunity to share their simulation of the star's life cycle, as well as the main arguments they presented during the debate on the fate of the Sun.
   • This discussion will allow students to see different perspectives on the same topic and also allow the teacher to correct any misunderstandings or incorrect information that may have arisen during the activities.
   • The teacher can ask targeted questions to each group to encourage a deeper discussion, such as 'Why did you choose to represent this stage of the star's life cycle in this way?' or 'What were the strongest points of the opposing group's argument during the debate?'

2. Connection to theory (3 - 5 minutes)

   • The teacher should then make the connection between practical activities and the theory of the life cycle of stars. They can briefly review the main points of the theory, such as the birth of a star from a cloud of gas and dust, the nuclear fusion that occurs during the star's life, and the different possible endings for a star, depending on its mass.
   • The teacher should explain how the simulations of the star's life cycle and the debate on the fate of the Sun help illustrate these theoretical concepts. For example, they can highlight how the simulation shows the transformation of the star over time, and how the debate forced students to research and understand the differences between a supernova and a white dwarf.

3. Individual reflection (2 - 3 minutes)

   • Finally, the teacher should reserve a few minutes for individual reflection. They can ask students to close their eyes and think about what they learned during the lesson.
   • The teacher can then ask questions to stimulate reflection, such as 'What was the most important concept you learned today?' and 'What questions do you still have about the evolution of stars?'
   • Students will have the opportunity to share their answers if they wish, and the teacher can use this information to adjust future lessons and ensure that all questions and confusions are addressed.

Conclusion (5 - 7 minutes)

1. Recap of Key Concepts (2 - 3 minutes)

   • The teacher should start the conclusion by recapping the main concepts covered in the lesson. This includes the life cycle of stars, the formation of a supernova, and the evolutionary cycle of the Sun.
   • The teacher can do this through a quick review in a question-and-answer format, where they ask a relevant question and students answer together. This not only reinforces the material learned but also allows the teacher to assess students' knowledge retention.

2. Connections between Theory and Practice (1 - 2 minutes)

   • Next, the teacher should highlight how the lesson connected theory and practice. They can emphasize how practical activities, such as the simulation of the star's life cycle and the debate on the fate of the Sun, helped illustrate and deepen the understanding of theoretical concepts.
   • The teacher can also point out that the argumentation and debate practice used in activity 2 is an important skill not only for science but for many other aspects of life.

3. Supplementary Materials (1 - 2 minutes)

   • The teacher should then suggest supplementary materials for students to explore after the lesson. This may include educational videos on stellar evolution, books or articles on astronomy, or interactive websites that allow students to visualize and experience stellar evolution.
   • The teacher should encourage students to explore these materials on their own, reinforcing the idea that learning continues outside the classroom.

4. Importance of the Subject (1 minute)

   • Finally, the teacher should conclude the lesson by explaining the importance of studying stars and astronomy in everyday life.
   • They can mention how understanding the life cycle of stars and the formation of supernovae help us understand the origin of chemical elements on Earth, the nature of the universe, and Earth's place in the cosmos.
   • The teacher can also highlight how the skills developed and practiced during the lesson, such as observation, interpretation, and critical thinking, are useful in many other areas of life.

By the end of the lesson, students should have a clear understanding of the life cycle of stars, including the evolutionary cycle of the Sun, and be able to analyze and discuss the possible fate of a star, such as the formation of a supernova. Additionally, they should have developed important skills in observation, interpretation, and critical thinking, and have an appreciation for the importance of astronomy in everyday life.