Objectives (5 - 7 minutes)

1. Understand the different types of stars, their characteristics, and how they are formed.

2. Identify the stages of a star's life, from its formation to its death (explosion or collapse).

3. Develop the ability to classify stars based on their characteristics, such as size, temperature, and brightness.

Secondary Objectives:

• Stimulate students' critical and analytical thinking by exploring the complexities of the universe and the formation of stars.

• Promote group discussion and collaboration among students, encouraging them to share their ideas and opinions on the subject.

• Encourage independent research and self-directed learning by asking students to research more about the topic before class and complete follow-up tasks after class.

Introduction (10 - 12 minutes)

1. Review of Previous Content: The teacher starts the lesson by reviewing the concepts of universe formation, galaxies, and solar systems, briefly explaining how stars are formed and the crucial role they play in our universe. It is important to review some terms that will be used in the lesson, such as nuclear fusion, nebula, and supernova. (3 - 5 minutes)

2. Problem-Solving Scenarios: The teacher presents two problem-solving scenarios to arouse students' interest and contextualize the subject. The first scenario could be: 'Why do stars have different colors?' and the second: 'How can astronomers determine the age and evolution of a star millions of light-years away?' (2 - 3 minutes)

3. Contextualization: The teacher highlights the importance of studying stars, mentioning how they are fundamental for the existence of life on Earth, as it is the energy from the Sun, a star, that allows life to exist on our planet. In addition, the teacher may mention how the study of stars has contributed to our understanding of the universe and the development of technologies, such as space telescopes. (1 - 2 minutes)

4. Gaining Attention: To capture students' attention, the teacher can share some curiosities about stars. For example, they can mention that the Sun is a medium-sized star, but there are stars that are thousands of times larger, like Betelgeuse, which is so large that if it were in the place of the Sun, it would swallow all the planets up to Mars. Another curiosity is that when we look at the night sky, most of the stars we see may have already died, but their light is still reaching us, as the light from stars takes time to travel the immense distance between them and us. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Activity 'Life Cycle of a Star' (10 - 12 minutes)

   • The teacher divides the class into groups of five students and distributes to each group a large colorful paper, colored pens, stickers, and magazine cutouts (which can represent gas clouds, stars, planets, etc.).

   • The teacher instructs the students to draw a large cycle-shaped diagram, representing the life cycle of a star, from its formation from a gas cloud (nebula) to its death (explosion or collapse). Students should include the following stages: nebula, protostar, main sequence star, red giant, supernova, white dwarf/neutrons/black hole.

   • While the students draw, the teacher circulates around the room, providing guidance and clarifying doubts. The teacher can also provide stickers and magazine cutouts to help students create the diagram.

   • After completing the diagram, each group presents their work to the class, explaining the stages of the life cycle of a star they represented and why they chose to represent them that way.

2. Activity 'Classifying Stars' (10 - 12 minutes)

   • Still in groups, students receive cards with information about different stars, such as their temperature, size, age, chemical composition, and life stage. Each group receives a different set of cards, ensuring that all types of stars (dwarfs, giants, supergiants, etc.) are represented.

   • The challenge is for students to classify the stars according to the information provided on the cards. They must justify their classification, explaining which characteristics of the star led them to make that decision.

   • After the activity, each group presents the stars they classified and their justifications to the class. The teacher can provide feedback and clarify any misunderstandings.

   • This activity promotes students' understanding of the different characteristics of stars and how they can be used to classify them. In addition, group discussion helps develop students' communication and collaboration skills.

3. Activity 'Stars in the Universe' (5 - 6 minutes)

   • Still in groups, students receive a research task. They must research a specific star (which can be chosen by the teacher or by the students themselves) and prepare a brief presentation about it, including information about its formation, characteristics, and current life stage.

   • Each group has a limited time to conduct the research and prepare the presentation. After the set time, the groups present their research to the class.

   • This activity promotes independent research and self-directed learning, as well as deepening students' knowledge about a specific type of star. The presentation to the class also helps develop students' presentation and communication skills.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes)

   • The teacher gathers all students in a circle and initiates a group discussion. They ask each group to share the solutions or conclusions found during the activities.

   • Students are encouraged to explain their choices and justifications, and to question the ideas of other groups. The teacher acts as a facilitator, ensuring that all students have the opportunity to speak and that the discussion remains focused on the topic.

   • This discussion promotes the exchange of ideas and critical thinking, while helping the teacher assess students' understanding of the subject.

2. Connection to Theory (2 - 3 minutes)

   • After the discussion, the teacher briefly reviews the theoretical concepts presented in the lesson and makes connections with the practical activities carried out.

   • The teacher highlights how the activities helped illustrate and deepen students' understanding of the different types of stars and their life cycle.

   • This step helps consolidate the knowledge acquired during the lesson and reinforce the importance of theory combined with practice.

3. Final Reflection (3 - 4 minutes)

   • The teacher proposes that students reflect for a minute on the following questions: 'What was the most important concept learned today?' and 'What questions have not been answered yet?'.

   • After the minute of reflection, the teacher invites students to share their answers with the class. The teacher listens attentively to students' responses and addresses any doubts or questions that may have arisen.

   • This step helps consolidate students' learning and identify any gaps in their understanding that may need further clarification. Additionally, it promotes self-assessment and metacognitive awareness, skills that are essential for self-directed learning.

4. Closure (1 minute)

   • To conclude the lesson, the teacher thanks the students for their participation and engagement, reinforcing the importance of the topic studied and encouraging them to continue exploring the fascinating world of astronomy.

   • The teacher may also suggest additional readings, videos, or websites for students who wish to further deepen their knowledge on the subject.

Conclusion (5 - 7 minutes)

1. Summary and Recapitulation (2 - 3 minutes)

   • The teacher starts the Conclusion by summarizing the key points of the lesson, recalling the life cycle of a star, the different types of stars, and how they are classified.

   • They also highlight the main discoveries and conclusions reached by students during the practical activities, reinforcing the importance of observation and experimentation in learning.

2. Theory-Practice-Application Connection (1 - 2 minutes)

   • The teacher then makes the connection between theory, practice, and application of the content. They emphasize how the knowledge acquired in the lesson can be applied to better understand the universe around us, including our own solar system and the stars that compose it.

   • They may also mention how the study of stars has practical implications, such as the possibility of finding other habitable planets or using star energy in innovative ways.

3. Additional Materials (1 minute)

   • The teacher suggests additional materials for those students who wish to deepen their knowledge on the subject. These may include books, documentaries, astronomy websites, space simulation apps, among others.

   • They reinforce that learning is a continuous process and that curiosity and the pursuit of new knowledge are essential characteristics for every student.

4. Relevance of the Subject (1 minute)

   • Finally, the teacher highlights the importance of the subject studied for students' daily lives. They emphasize that although stars may seem very distant and inaccessible, they play a fundamental role in our existence, providing the necessary energy for life on Earth.

   • Additionally, they may mention that the study of stars can inspire new generations of scientists and engineers, motivating them to explore the universe and develop new technologies that can benefit humanity.

   • The teacher encourages students to remain curious and open to new discoveries, reminding them that science is a collective process in which everyone can contribute to expanding our knowledge of the world and the universe.