July 19

Today I started reducing images! I was confused on the tutorial (they use different data and it wasn't clear to me if some parts still applied to our data or which file they were referring to) and Lydia nicely met with me after lunch and answered all of my questions.

First I practiced on the V band images, getting used to the program and the process:

Here are before and after pictures of the V band images.

Later, I struck out on my own (with Lydia right next to me for support) to reduce the I band images. I made a beautiful master flat:

Due to variations in pixel size, dust grain in the optical surfaces and more, even if there is a uniform light source the count level across the image can vary significantly. 

The master flat accounts for variations in count level across the image (we subtract the master flat from the science images).

It was a very productive afternoon!