Homework #2:  GetFit and StackImages...

Open a "terminal" window.  On a Mac, this is called "Terminal".  On a PC, it is called "Command Prompt".
Navigate to your BobsAstro folder and type:

        conda activate BobsAstro
        pythonw -m GetFit

IMPORTANT NOTE:   If your computer is a Windows computer, the "pythonw" command probably won't work.  
If it doesn't work, use "python" instead of "pythonw".

The GetFit app's window will pop up.  
In the "Website:" textfield type:

        https://vanderbei.princeton.edu/fits_files/m27_dumbbell

In the "File list:" textfield, add these fits file names:

22_51_01_Stack_16bits_10frames_300s.fit
22_16_45_Stack_16bits_10frames_300s.fit
21_09_57_Stack_16bits_10frames_300s.fit
22_45_18_Stack_16bits_10frames_300s.fit
22_11_03_Stack_16bits_10frames_300s.fit
21_04_14_Stack_16bits_10frames_300s.fit
22_39_35_Stack_16bits_10frames_300s.fit
22_05_20_Stack_16bits_10frames_300s.fit
20_58_31_Stack_16bits_10frames_300s.fit
22_33_53_Stack_16bits_10frames_300s.fit
21_59_05_Stack_16bits_10frames_300s.fit
20_52_57_Stack_16bits_10frames_300s.fit
22_28_11_Stack_16bits_10frames_300s.fit
21_46_36_Stack_16bits_10frames_300s.fit
22_22_28_Stack_16bits_10frames_300s.fit
21_40_55_Stack_16bits_10frames_300s.fit

Note 1:  These files contain the raw image data that I acquired on the Dumbbell Nebula (aka M27) exactly one year ago (to the day).
Note 2:  These files are big.  On some any computers, the download is much quicker if one only downloads, say, three or four of these files at a time.   If you do it like that be sure to select the same "Download to:" folder for each download.

Click on the "Download to:" button and select the folder to which you'd like these files to be downloaded.
Then click on "Download Files" to do the download.
After all sixteen files are downloaded, you can close out of the "GetFit" app.

Problem 1:

In the terminal/prompt window type:

        pythonw -m StackImages

Click on "Select Images", navigate to the folder with the sixteen fits files and select all sixteen of them.  For "Align images using", select the "2 stars" option.  Then click on "Align/Stack/Show".  The stacked image will appear in a new window called "Figure 1".  Play with the slider bars to make the image look nice/realistic and then click on the "Save" button.  Close the StackImages app.

Problem 2:

Reopen the StackImages app and repeat the process you did above with the following small change...  Instead of using the "2 stars" alignment method, select "no stars".  And, before hitting the "Save" button, be sure to change the "File name" to a different name.  How/why does it look different from what you saw before?  Close the StackImages app.

Problem 3:

Again reopen the StackImages app and repeat the process you did in Problem 1 with the following small change...  Change the "Stacking Method" from "Outliers Removed" to "Max".  And again, before hitting the "Save" button, be sure to change the "File name" to a different name.  How/why does it look different from what you saw before?  Close the StackImages app.

Problem 4:

Lastly reopen the StackImages app and repeat the process you did in Problem 1 with the following small change.  After you get your stacked image, the button "Astrometric Analysis" will be available to click on.  Click on it.  It will compute exactly where the center of the picture is on the celestial sphere.  The coordinates are called Right Ascension (RA) and Declination (Dec).  It will also compute the size of each pixel in arcseconds and it will enable the "Deconvolve" button.  Click on that button to get a new, perhaps improved, version of the picture.  Play with the slider bars until you are happy and then save the image.  Do you think this new image is better or worse than the one from Problem 1?  Close the StackImages app.

Prepare a document, such as a Word document or a pdf file, that contains the saved images and your response to the questions.