Classroom Activities
The student learning objectives at the end of this curriculum unit are to demonstrate their understanding of how scientists analyze and characterize stars using blackbody curves, emission and absorption spectra, Doppler effect, and Hertzsprung-Russel diagram. With a vault of information from NASA’s various programs such as, living with a Star, and the findings from powerful instruments such as Solar Dynamic Observatory and the Daniel K. Inouye Solar Telescope students can explore surface features of the sun, and discuss how the Sun’s solar weather affects human activities on Earth and in space.
Blackbody Radiation Curve Activity: Star Temperature, Color, and Radiance
In the PhET Colorado Black Body Spectrum Activity, students will describe what happens to the blackbody spectrum when the temperature is increased or decreases and what observations they make about the shape of the curve.52 In this activity, students will be able to determine the temperature and color of the stars. They will explain the relationship between the temperature and the peak wavelength. This is an online virtual simulation activity.
Periodic Table of Spectra: Chemical Composition of Stars
Students will be given a standard Periodic table of elements and a Periodic Table of Spectra. In this whole-class activity, students will compare how each chart represents the elements and explain the information that each of the documents provides. Regarding the Periodic Table of Spectra, students will observe that each element has its unique spectral lines.53 Using the unique “fingerprint” of each element, students will understand how scientists can identify the chemical composition of celestial bodies and the evolutionary stage of a star from their spectral lines. At this point, students may want to know how each element has its unique spectrum. The teacher can provide resources to explain the Bohr Model and the particle nature of light as photons.
Stellar Spectral Lines Analysis: Star Composition and Temperature
In the Explore Learning Star Spectra activity, students will determine the elements that are present in a star by comparing its absorption spectrum to known spectra of elements such as carbon, hydrogen, helium, sodium, magnesium, calcium, and iron. Use the information to infer the approximate temperature of the star. In this activity, students will see how astronomers use spectroscopy, and how powerful this technique is in the classification of stars.54
Hertzsprung-Russell Diagram: Temperature, Luminosity, Size, Color, and Evolutionary Stage
Students will be given a worksheet of a Hertzsprung-Russell diagram.55 As students read and interpret the HR diagram, which is a graphical representation of the relationship between a star’s absolute temperature and its luminosity. Students will recognize that unlike conventional associations of color and temperature, for stars cooler stars are red and hotter stars are blue-white. Students will use the chart to classify stars by temperature, color, luminosity, evolutionary stage, and size.
Doppler Effect with Demos: Observing Stellar Motion using Blueshifts and Red Shifts
Students will be shown a video explaining the Doppler effect.56 In this video, they will see how light, and sound have an apparent change in pitch as it approaches or moves away from them as the observer. While they might not have known the term, Doppler effect, they will now as they have experienced emergency vehicles with flashing lights and blaring sirens motion towards or away from them. You can demonstrate the Doppler effect in the classroom in several ways. One way is by having a speaker with sound on and spin it around your head. A Doppler ball consists of a foam ball with a battery-powered buzzer inside. Students will throw the ball back and forth and recognize the frequency shift as they through it away to their partner, a redshift. When we catch the approaching ball, the pitch should sound higher. This is a blue shift. A third option is to use a long sound tube and spin it around.57
Frayer Model: Vocabulary Building for English Language Learners
In addition to other vocabulary-building techniques, students will be given a modified Frayer Model to include the vocabulary words in their language. Numerous Frayer Models are available online, for one of the segments students will write the word in their native language. In this exercise, students may already know the word, and if not then they can use a translation dictionary.
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