skim chapter 12.5-12.8, focus on 12.6 Do you have any questions?
Review: What is a binary star?
Spectroscopic binary stars have some of their light redshifted, and some blueshifted. Why?
Review: What is the difference between luminosity and magnitude
how much does it bother you that warm colored stars have a lower temperature than cool colored stars
How much does it bother you that the the H-R diagram goes from cool colors to warm colors, and therefore the temperature decreases along the x axis
Watch the following video on the H-R diagram Do you have any questions
what has a higher temperature, the cup of coffee, or the iceberg?
Temperature is a measure of _average heat_. So what has more heat, a cup of coffee, or an iceberg?
If the average temperature of Betelgeuse is so much lower than our sun, how does it have such a higher luminosity?
He challenges you to have a discussion on this in class. Come up with three things to discuss from the video. they can be questions of points that didn't make sense, the difference between seeing exponential difference on the video vs the exponential scale in the diagram, something that made you wonder, etc etc etc.
Categorize your understanding
What the H-R diagram shows
How to read the H-R diagram
How to read the logarithmic scale of the y-axis of H-R diagram
what the different colors on the HR diagram signify
What the "main sequence" of the HR diagram represents
I've got it
I'm fuzzy
So confused