You should be able to discuss the significance of the center of mass of a pair of objects in mutual orbit how we can find the masses of stars in a visual binary (words, not math) the types of information that can be obtained from the study of the light curve of an eclipsing binary and how the information is obtained You should be able to describe the different classifications of binary stars.

	You should be able to describe: how we can use the H-R diagram to find the distance to a star or star cluster how mass, radius, luminosity and temperature are related for main sequence stars
	You should be able to discuss the Hertzsprung-Russell diagram in detail (e.g. what is plotted on each axis, what the scales are, label the different regions of the graph, how many stars are in each of the regions)

Note: we really did the last two of these items in Week 9.

Outside of class: Read Ch. 12 Sections 5-7.  Go over the rest of the Chapter 12 review questions. 

Outside of class: Read  Chapter 13.