Observing Session #3

5pm Thursday, December 12

I’m ready to test things. I’ve made a series of software changes:

• When the software is unable to measure the blurriness of an image (because it’s too blurry), the rest of the software will correctly ignore the focus of that image.
• All blurriness measurements are adjusted based on the image’s height above the horizon — this should prevent the software from getting upset because images are getting fuzzy solely because they are close to the horizon.

Weather forecast is lousy, but there may be a few hours of thin, scattered clouds right after sunset. I can use that to try and test this new software. Let’s see what happens……

Aha! (4 hours later)

Yes, the clouds rolled in. However, things look much better than before. I have a total of 207 images, although only the first 100 are cloud-free. However, all except the last 6 images will yield a brightness measurement. Focus remained good throughout. The resulting light curve looks like this (the arrival of the clouds is really obvious):

Pretty soon we’ll have enough data points to do something interesting . . .