Life of a Star. Lesson development

Transcription

1 Lesson development InstructIonal objectives Students will compare various life cycles; interpret charts and diagrams depicting the life cycle of stars; use a variety of Internet sources to research stages of a Sun-like star s life cycle; develop PowerPoint presentations or Web pages to visualize the stages of a star s life cycle; compare the life cycle of a Sun-like star to the life cycle of a massive star; and gather and share data about stars with people around the world. background Stars are born in dark, cold nurseries filled with dust and gas. Gravity s pull clumps this dust and gas together forming protostars. As protostars contract, their matter collides, heats up and begins to glow. Eventually, the protostar s central core is hot enough to begin hydrogen fusion. The protostar will grow and change into a main-sequence star. The Sun is a middle-aged main-sequence star. For the past 4.6 billion years it has been relatively stable and should continue to be for another 5 billion years. Old age for the Sun will be more spectacular than middle age. It is expected to expand, becoming a red Giant, perhaps twice during its later years.these showy final years will lead to a much quieter death. The Sun will shed its outer layers, fade and become a planetary nebula. All that will be left will be an extremely hot core that will slowly cool and eventually become a white dwarf. A star s cycle of birth, life, death, and rebirth in the universe is never-ending, unfolding in millions and billions of years. Changes in individual stars cannot be observed. But, by observing many star clusters at various stages, astronomers have pieced together what they believe to be a star s entire life cycle. This process has been aided by the launch of space observatories. In particular, since the launch of the Hubble Space Telescope in 1990, NASA has been able to peer deeper and deeper into the universe. The results have produced spectacular images and snapshots of stars in every stage of stellar evolution.

2 Lesson development (continued) ENGAGE Use the images of Chimchar and the Sun to begin a discussion of life cycles with your students (TEACHER RESOURCE). These questions may help guide your discussion: In the Pokémon world, how might Chimchar change in appearance and capabilities? Use the Pokédex, found at the official Pokémon Website, to compare Chimchar to Monferno and Infernape. In our world, where would you classify our Sun in its life cycle? What criteria did you use for this classification? How might the Sun change? What causes these changes? EXPLORE A. Agree/Disagree Pre-assess your students prior knowledge of stars and the Sun with this agree/disagree activity. The Sun Post I agree and I disagree signs on opposite walls in the classroom. For each statement below, ask students to walk to the sign that represents whether they agree or disagree with the statement. If they are unsure, ask students to stand in the middle of the Chimchar room. In their groups, ask students to discuss their ideas. Encourage all groups to share their ideas. The Sun is a star. All stars are exactly the same. Stars in a constellation are close to each other. Stars live forever. All stars will end their lives the same way as supernovae. Short explanations for each statement can be found at the Amazing Space Website, amazing-space.stsci.edu/resources/myths/stars.php.p=teaching+tools%40%2ceds%2 Ctools%2C%3EStellar+evolution%40%2Ceds%2Ctools%2Ctopic%2Cstars.php%3EOverview% 3A+Star+myths%40%2Ceds%2Coverviews%2Cmyths%2Cstars.php&a=%2Ceds B. Life Cycle of the Sun 1. Use these questions to help your students analyze the chart of the Sun s life cycle (TEACHER RESOURCE). How long is the Sun s life cycle? Life Cycle of the Sun Where is the Sun in its life cycle? What stages will the Sun travel through, from the point marked Now to its death? 2. Show your students the drawing you find at main.html that compares human and star life cycles. 3. Group your students into teams of three.

3 Lesson development (continued) 4. Randomly assign each member of the team Task Card 1, Task Card 2 or Task Card 3 (STUDENT RESOURCE). Each Task Card identifies which part of the Sun s life cycle the student will research and lists appropriate Websites for research. The Website links are interactive. If possible, allow students to work from the PDF file on a computer that has Internet access. 5. Re-organize students so that the students working on similar sections of the life cycle may work together. For example, arrange the room and materials so that everyone working on the birth of a star may share materials and work collaboratively. 6. Use these general questions to help guide your students research: What happens during this stage? What s the average time a star is in this stage? How does the star change during this stage? What causes this change? 7. Once students have completed their research, pull them back into their original teams to share what they ve learned. explain A. This poster depicts the Life Cycles of Stars and can be found at NASA s Imagine the Universe Website: The Life Cycle of Stars It can be printed or viewed from the Website. Use this poster to help students piece together their research about the life cycle of a Sun-like star. B. Many sites include visual representations of a star s life cycle. Ask your students to use these sites to help review what they ve learned about the life cycle of our Sun. The Sky: Life Cycle of a Star Where Do Stars Come From? And Where Do They Go? Small Star Sequence elaborate There are many interesting ways for your students to showcase the life cycle of our Sun using technology. They should work as a team to pull their individual research into one story using the information and images they ve discovered. Students may: create a PowerPoint presentation create a Web Page Before you begin, you may want your students to use a storyboard to help them plan and organize their projects. One example of a storyboard can be found at It may also be helpful for your students to review these Nortel LearniT video tutorials for help in creating their PowerPoint presentations and Web pages. They can be found at and

4 Lesson development (continued) Your students may want to use images found during their review of Websites in the EXPLORE and EXPLAIN sections of this lesson. They can either download those pictures to the hard drive, or save the URL as a Favorite in the Web browser. Encourage your students to put a descriptive title screen, credits and references at the end of the project. Please remind students to use only images that they have permission to include. Review copyright and copywrongs by watching the Nortel LearniT video tutorial at Students may want to create an animation or Webquest to demonstrate their understanding of the life cycle of a star. Examples of each are below: Animations - Life of the Sun - Canadian Space Agency s Applet: The Life Cycle of a Star media/unit2/star_lifecycle/star_lifecycle.html WebQuest - Life Cycle of Stars EVALUATE Based upon the image of the Orion Nebula (TEACHER RESOURCE), ask your students these questions: What stage of life has this Hubble telescope image captured? What stages would you expect to see following this step in a star s life cycle? This image, and others, can be found in a Washington Post article, The Hubble Cosmos Postcards from the Edge: wp-srv/photo/galleries/hubble/3.htm. Several of these images at this site may be used to help evaluate your students understanding of the life cycle of stars. Orion Nebula Use NASA s Imagine the Universe maze to check your students understanding of stars and their life cycle.

5 Lesson development (continued) To evaluate the PowerPoint presentation and Web pages, use these rubrics found at the Nortel LearniT site: PowerPoint Presentations Web pages (Webpage Creation and Website Project) extend These activities may be used to extend or continue your students exploration. A. EXPERT INTERVIEWS -- WHAT DO YOU WONDER NOW? What are your students wondering now that they ve learned more about the life cycle of stars? Generate a list of questions that your students might ask the experts from NASA, the National Institute of Aerospace and research universities. Submit this list following the link on this Website. Several questions from all submitted will be used in video interviews with experts and posted to this site. B. Explore these Websites to compare the life cycle of Sun-like stars to the life cycle of massive stars. NASA s Imagine the Universe: Supernovae NASA s StarChild Website C. Find out more about attributes of individual stars by exploring these Websites. Windows to the Universe: All Stars Line Up Windows to the Universe: ExploraTour: A Peek Into the Lives of Stars Amazing Space: Star Light, Star Bright D. Join others across the world to see if people everywhere see the same number of stars in the night sky. The Student Observation Network: Star Count Project encourages students and adults to count the number of stars viewed each night. This data is shared with others around the world. Everything you need to know to run this challenge is found at the Star Count Website:

6 Teacher resource Chimchar Image: NASA The SUN (For a QuickTime movie)

7 Teacher resource Illustration:Tablizer; Science Museum of Minnesota Life Cycle of the Sun

8 student resource task card 1: BIrTH OF a sun-like star You will become an expert on the birth of a Sun-like star. During your research, be sure to look for more information about these topics: Gas clouds Protostars These Websites will help with your research: HubbleSite NASA s Imagine the Universe Section I: Star Birth The Birth of Stars The Once and Future Sun The Life and Death of Stars The Life Cycle of a Sun-Like Star

9 student resource task card 2: MId-LIFe OF a sun-like star You will become an expert on the mid-life of a Sun-like star. During your research, be sure to look for more information about these topics: Today s Sun Red Giant These Websites will help with your research: NASA s Imagine the Universe Section I: Star Birth and Life and Section II: Beginning of the End NASA s StarChild Website: The Sun NASA s STEREO Mission Website: The Sun in 3D The Once and Future Sun The Life and Death of Stars The Life Cycle of a Sun-Like Star StarDate Online: Exploding Stars

10 student resource task card 3: OLd age TO THe death OF a sun-like star You will become an expert on the old age to the death of a Sun-like star. During your research, be sure to look for more information about these topics: Red Giants Planetary Nebula White Dwarfs These Websites will help with your research: HubbleSite NASA s Imagine the Universe Section III: The End The Death of Stars Amazing Space %2Ceds%2Ctools%2C%3EScience+content+reading%40%2Ceds%2Ctools%2Ctype% 2Creading.php%3EOverview%3A+End+of+stellar+life+story%40%2Ceds%2Coverview s%2ctales%2cglorious_end.php%3etales+of%3a+end+of+stellar+life%40%2cresour ces%2ctales%2cglorious_end.php&a=%2ceds The Once and Future Sun The Life and Death of Stars The Life Cycle of a Sun-Like Star 0

11 Teacher resource Image: Rice University and NASA orion nebula