PHYS 454, Homework 4

Spring 2024

1. Limb Darkening

   Read the following sections about Limb Darkening found here: Limb Darkening

   Find an image of the sun in the visible wavelengths from here: NASA Solar Dynamics

   Use Python to:

   1. Extract a line profile of intensity from the solar image that shows the decline in brightness (i.e. limb darkening) as a function of distance from the center
   2. Prepare an analytical plot using the theory conclusions in the attached pdf
   3. Prepare one final plot with both the observed limb darkening and the theoretical darkening curves.

2. Balls of Gas

   Research a Giant molecular cloud of your choosing. Try to find/make an estimate for the average density of the cloud. Use that to compute a time required for a free fall collapse of that cloud.

3. Eclipse

   On April 8, there will be a partial eclipse over NYC. It will occur during the hours of 2pm and 4pm roughly. Weather permitting, go outside and try to observe the crescent shadows that occur as the sun is partially blocked by the moon.
   1. Take a picture of them. Note the time and confirm with a prediction of the eclipse that your shadows make sense.
   2. Write a short poem about your experience.

For all

• Include your sources and a table of the raw data you used. (This ideally would be a link to your data file online somewhere, like a github repository or google drive link. Make sure sharing is set properly so that with a single click, it can be viewed.)
• Make sure all plots are formatted nicely and have labeled axes.

Due Date: Wednesday April 10, start of class. (via blackboard)

Prepare your work in a typed (no handwritten math or drawn diagrams), document (pdf) with plots and any citations for any references you used, and links to any extensive code you wrote that was used.