ël Gizmos Name: Anvith Kothuri and Skanda Begari Date: 10/30/21 Student Exploration: Star Spectra Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: absorption spectrum, binary star, blueshift, Cepheid variable, emission spectrum, giant star, nebula, redshift, spectrum, star Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. What happens when light goes through a prism? When the light goes through a prism, it is bent or refracted. This band of colors is called a spectrum. 2. A rainbow is an example of a spectrum. What is the sequence of colors in a rainbow? Violet, Indigo, Blue, Green, Yellow, Orange, Red. Gizmo Warm-up The interior of a star produces a continuous spectrum of light, like a rainbow. Cooler gases in the outer layers of the star absorb certain wavelengths of light, causing dark lines to appear in the spectrum. The resulting absorption spectrum can tell astronomers a great deal about the star. 12 1. On the Star Spectra Gizmo, turn on Show labels. Select star 1 to see its absorption spectrum. How many lines do you see in the spectrum? 10 7 10 lines 2. Drag the Hydrogen spectrum next to the Star spectrum so that the edges line up. Do some of the lines on the two spectra match up? Yes, four of the lines on the spectra line up. 3. Drag the Helium spectrum next to the Star spectrum. Do some lines match? Yes, 6 lines match up on the spectra 4. Try out the other available spectra. Do any others have lines that match? No 5. Which elements have contributed to the spectrum of star 1? Hydrogen and Helium match up with star Reproduction for educational use only. Public sharing or posting prohibited. @ 2020 ExploreLearning™ All rights reserved
1's spectrum. Note: The elements in a star's spectrum do not necessarily reflect what the star is made of. The absorption spectrum is mostly determined by the surface temperature of the star. Activity A: Get the Gizmo ready: . Check that Show labels is on and Neutral spectra is selected. Classifying stars Question: How are stars classified? Sodium Introduction: Late in the 19th century, Harvard astronomer Edward Pickering wanted to sort and catalog the thousands of star spectra that had been collected by the Harvard Observatory. He hired several women to do the work, paying them 25 cents a day. The most prominent of these women was Annie Jump Cannon, who devised a classification system still used today. Class O Blue B Blue-white A F G K M Color White White Yellow Orange Red Harvard Classification Scheme Prominent spectral lines Ionized helium, hydrogen Neutral helium, hydrogen 11,000 - 25,000 Hydrogen, ionized sodium, ionized calcium Hydrogen, ionized sodium and calcium; neutral sodium and calcium 6,000 - 7,500 Neutral sodium and calcium, ionized calcium, ionized iron, ionized magnesium 5,000 - 6,000 Neutral calcium, neutral iron, neutral magnesium Neutral iron, neutral magnesium, and neutral titanium oxide (not shown) < 3,500