b. Based on the "photographs" and the indicated dates, which variables show enough of their brightness cycle to allow the determination of their period? C. Which variable star has the most reliably determined period, and approximately what is the Why isn't it possible to find a period for each of the vanable stars? Is it possible to determine an amplitude for star E, if the magnitudes of the comparison stars are known? Explain. In the simulated photograph for May 10 star positions have been marked A - G Use appropriate size dots to indicate the predicted apparent brightness of each star for the date shown