PART5:https://www.youtube.com/watch?v=3tCMd1ytvWg

PART6:https://www.youtube.com/watch?v=rut6fr28TlE

https://www.youtube.com/watch?v=uakl4vvRB8U Look at these.

1:See these two Your Turn questions in the online lecture on Cosmology (slides 5 and 6) or you can see just the questions themselves on this YouTube page. YT Mass Distribution

The above figure is similar to the one in the video, but shows the actual orbits for stars located at A, B, C, and D, which may help with your visualization and answer to the first problem.

Please choose your own constellations and galaxies.

2:Compare the galaxies in your constellation (you may want to compare to the group's constellations) and predict which one is likely to be the least massive. Explain your choice. Calculate the mass of this galaxy. Note: This is a practice for the Galaxy Mass constellation question, so you can use thetutorial to help you with this assignment.