H_R_Diagram_Gizmo_Lab.pdf

Date: Student Exploration: H-R Diagram Vocabulary: giant, H-R diagram, luminosity, main sequence, star, supergiant, white dwarf Gizmo Warm-up In the early 1900s, astronomers identified many star characteristics such as color, size, temperature, and luminosity—or how bright a star is. Using the H-R Diagram Gizmo, you will discover how some of these characteristics are related. Start by moving your cursor over the stars in the Star collection. Star information is displayed on the right side of the Gizmo. The numbers given for Luminosity, Radius, and Mass are in comparison to the Sun. So, a star with a radius of “2 Suns” is twice as large as the Sun. Temperature is given using the Kelvin scale, where 273.15 K = 0 °C and 373.15 K = 100 °C. 1. Find Betelgeuse in the Star collection. Fill out the chart at right. 2. The Sun has a radius of 695,500 km. What is the radius of Betelgeuse? Betelgeuse has a radius of 1000 km. Activity A: Color and temperature Get the Gizmo ready: • Make sure Arrange stars is selected and Color is selected on the Arranged by menu. Question: How is the color of a star related to its temperature? 1. Predict: If you look closely at some stars in the night sky, you can see slight differences in their color. Some stars look reddish. Others appear orange, white, or blue. What do you think the color of a star indicates about its temperature? The color of a star indicates the stars wavelength. The wavelength determines the stars temperature. The hotter the star, the more blue it is. The cooler the star, the more orange it is. 2. Organiz