Thursday, June 22, 2006

Astronomy Internship - Day 13

My day started today far earlier than I'd have liked it to. My roomate has gotten into a very annoying habit of setting his alarm extremely early and then hitting the snooze alarm repeatedly, for sometimes as much as an hour.

Unfortunately for me, I'm a light sleeper and once I'm awake, it generally takes me a half hour to get back to sleep. With an alarm going off every 10 minutes, this means that I don't get back to sleep.

Finally, he gets up at around 7:00. By 7:30 I'm just about to fall back asleep when the janitorial staff decides it would be a good idea to start vacuuming the hall outside my door. So I'm kept up for another half hour.

I finally decided to just sleep in and catch up on the sleep I'd lost.

I eventually got up around 10:00 and headed over to the astronomy building to play with DAOPHOT. The process did not go terribly smoothly.

The first problem I had is that, upon starting, it asks to confirm that a number of parameters are set correctly. Given that they were default values, I was quite sure that they were not. However, the logsheet for when the images were taken did not contain the information I needed. Thus, I had to find Dr. Sandquist and obtain the information from him.

My next problem was getting the images to open. It turns out that, since I had to go to Dr. Sandquist's directory on the server and was running the program from there, it wouldn't let me open images in my directory since I didn't have permission to do things in his directory.

Once we go the image open, the next thing to do was have the computer find all the stars in the image. Since it's a cluster I'm analyzing, there can be several hundred to a few thousand stars, which is why we make the computer do it.

Unfortunately, fine tuning the algorithm to do this is quite tricky. The first time through it was able to find the bright stars without any problem, but completely missed the dim ones, yet claimed to find several where there were none.

After a bit of tinkering, I was able to improve it slightly, and it picked up most real stars, with the exception of the faintest, but seemed to still be finding stars in completely blank fields.

I tinkered a bit longer and gave up for the day around 3:30 because staring at the computer was making my head hurt. I went back to my room and did some reading, and took a short nap before dinner.

After dinner I came back and laid down again because I had a migraine. Around 8:30, I went out for a walk which finally made my head feel better.

When I got back at 10:00 I began working on the Powerpoint presentation for our talks next week over our project. I'll be sure to post the Powerpoint file after the talk which should be next Friday.

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