Activity B: Get the Gizmo ready: Luminosity and 0 Select the DISTANCE tab. distance 0 Check that Luminosity vs. Period is selected. Introduction: Henrietta Leavitt observed Cepheids inside the Small Magellanic Cloud. a star clusterjust outside the Milky Way. All of these stars are about the same distance away. LeavilI found that the most luminous Cepheids had the longest periods. By relating each Cepheid's luminosity to its period, Leavitt discovered a way to nd the luminosity ot a Cepheid in any galaxy. By comparing the apparent brightness of a Cepheid variable to its known luminosity, the distance to any Cepheid (and its host galaxy) could then be determined. Goal: Find the mean luminosity and distance of Cepheid stars. 1. Collect data: On the DISTANCE tab, check that the Luminosity vs. Period graph is selected. Notice that as the period of a Cepheid variable increases. so does its luminosity. A luminosity of 2,000 Suns means that the star is 2.000 times brighter than the Sun. A. Based on the graph' what is the approximate mean luminosity of a Cepheid variable star with a period of 5 days? a period of 10days? Mean Luminosity